AC Electronic Load

Key Features：
-Power Rating : 1800W, 3600W, 4500W
-Voltage Range : 50V ~ 350Vrms
-Current Range : Up to 18Arms, 36Arms, 45Arms
-Peak Current : Up to 54A, 108A, 135A
-Parallel / 3-Phase Function
-Frequency Range : 45 ~ 440Hz, DC
-Crest Factor Range : 1.414 ~ 5.0
-Power Factor Range : 0 ~ 1 lead or lag (Rectified mode)
-CC, CR, CV, CP for DC Loading
-Constant & Rectified Load Modes for AC Loading
-Analog Voltage & Current Monitor
-Timing Measurement for Battery, UPS, Fuse and Breaker tests
-Measurement : V, I, PF, CF, P, Q, S, F, R, Ip+/- and THDv
-Short circuit simulation
-Full Protection : OC, OP, OT protection and OV alarm 

Complete AC & DC Load Simulations
Chroma's 63800 AC & DC Electronic Load is designed for both AC & DC Load Simulations. Illustrated below are the various load modes which are available:

AC Load Simulation
The Model 63800 AC & DC Electronic Load provides two unique operating modes for AC load simulation; (1) Constant Load Modes and (2) Rectified AC Load Modes. Each are described below.

Constant Load Modes
The Constant Load Modes allow users to set the following operating modes: CC, CR and CP mode. The CC & CP modes in this category allow users to program PF or CF, or both. For CR mode the PF is always set to 1.
The power factor range is limited based on crest factor programmed (Shown as Figure 1). If the programmed PF is positive then the current will lead the voltage waveform and when PF is set negative, the current will lag the voltage waveform. (See below)

Figure 1: Crest Factor vs. Power Factor control Range
CF SUB>I /SUB> = I peak / I rms
PF = True power / Apparent power

Rectified AC Load Modes
The 63800 AC & DC Electronic Load provides unique capability to simulate non-linear rectified loads for a wide range of testing applications. There are three load modes available for rectified load simulations: RLC, CP and Inrush Current.
Figure 2 shows the typical model of a rectifier input. Under RLC mode, users can set the RLC values to 100% and simulate the behavior of the actual UUT. Figure 3 & 4 compares the voltage and loading waveforms between the actual RLC built circuit and the simulated rectified circuit by using Chroma's RLC load mode. The waveform obtained under CC mode with the same loading crest factor shown in Figure 5.

Figure 2 : Typical Rectified Circuit

For inrush current simulation (See Figure 6), the 63800 provides an Inrush Current mode that allows the user to set different inrush current amplitude and voltage phase angle where the inrush current started.

     
Figure 3                             Figure 4

  
  Figure5                              Figure 6

DC Load Simulation
Chroma's 63800 DC load simulation includes four load modes : constant current, constant resistance, constant voltage and constant power as depicted below.
CC, CR, CP mode can be used for regulated voltage power supply testing. For battery charger, CV mode may help to check its current regulation.
Many inverter designs, although its input is DC, show an input current and will show rectified pattern. This unique load mode makes the Chroma 63800 load ideal for Fuel Cell, PV module/array and Battery testing.

Comprehensive Measurements
Chroma's 63800 Series AC & DC Electronic Loads include built-in 16-bits precision measurement circuits to measure the steady-state and transient responses for true RMS voltage, true RMS current, true power(P), apparent power(S), reactive power(Q), crest factor, power factor, THDv and peak repetitive current.
In additional to these discrete measurements, two analog outputs, one for voltage and one for current, are provided as a convenient means of monitoring these signals via an external oscilloscope.

Timing Measurement
Timing parameters are critical to many products such as UPS's Breakers and Fuses. The 63800 AC & DC Load also includes a unique timing and measurement function to measure the trip time of fuses & circuit breakers or the transfer time for UPS's (Off-Line).

Figure 7: Transfer time for Off-Line UPS

Automatic Bandwidth Adjustment (ABA)
When the UUT, such as one shown in Figure 8, has a higher output impedance, the current waveform will not be stable without ABA. In most cases, the loading current will be oscillating and spoil the test.

  
Figure 8: Fixed Bandwidth                      Figure 9: With ABA
Note 1: A test current will be programmed prior the actual loading defined by user for impedance detection.

Parallel / 3-Phase Control
The 63800 series provides parallel and 3-phase functions for high power and three phase applications. All the models within the 63800 series can be used together for both parallel and 3-phase functions as well as parall