Programmable AC/DC electronic load

The Chroma 63800 programmable AC/DC electronic load is mainly used for testing products such as uninterruptible power systems (UPS), off grid inverters, vehicle inverters, AC power supplies, and other power components such as switches, circuit breakers, fuses, and connectors.

　　Chroma 63800Programmable AC/DC electronic loadMainly used for testing products such as uninterruptible power systems (UPS), off grid inverters, vehicle inverters, AC power supplies, and other power components such as switches, circuit breakers, fuses, and connectors.

The 63800 series can simulate load conditions under high peak factors, and even compensate for power factors in real time when the voltage waveform is distorted. This feature makes the ability to simulate loads more realistic and prevents voltage overstress, thus obtaining more reliable and fair test results.

The 63800 series has developed an RLC operation mode using DSP technology to simulate nonlinear rectification loads. In addition, stability can be improved by detecting the impedance of the test object, and the bandwidth can be dynamically adjusted to ensure system stability.

The 63800 series has a time measurement function that allows users to measure key time parameters such as battery discharge time, fuse blowing time, circuit breaker tripping time, and UPS conversion time.

In terms of measurement, the 63800 series can provide users with a wide range of monitoring output performance for the tested object. In addition, voltage and current can be transmitted to the oscilloscope for monitoring through the built-in analog output signal and BNC cable. The GPIB and RS232 interfaces provide remote control and monitoring functions required for system integration.

The 63800 series has the function of fan speed control, which adjusts the wind speed according to the load power, so as to maintain low noise as much as possible during use. In addition, it also has a self diagnostic function to ensure that it maintains a normal state during routine startup. The protection alarm function includes protection against over power, over current, over voltage, and over temperature.

Chroma 63800 Programmable AC/DC Electronic LoadMain features:

Power range: 1800W, 3600W, 4500W

Voltage range: 50V~350Vrms

Current range: up to 18Arms, 36Arms, 45Arms

Peak current: up to 54A, 108A, 135A

Parallel/three-phase control

Frequency range: 45~440Hz, DC

Peak factor range: 1.414~5.0

Power factor range: 0~1 leading or lagging (rectification mode)

DC load: constant current, constant resistance, constant voltage, constant power

AC load: general load mode and rectifier load mode

Simulate voltage and current monitoring

Time measurement: can be applied to batteries UPS、 Testing of fuses and circuit breakers, etc

量测 : V, I, PF, CF, P, Q, S, F, R Ip+/- and THDv

Short circuit simulation

Protection function: Over power, over-current, over-voltage, and over temperature protection

GPIB and RS-232 control interfaces

　　Complete simulation of AC and DC loads

The 63800 series AC/DC electronic loads are mainly used for simulating AC and DC loads. The following tree diagram shows the various load modes available.

　　Communication load simulation

The 63800 series AC/DC electronic load provides two operating modes for AC load simulation testing: (1) general load mode and (2) rectifier load mode. The description is as follows:

　　General load mode

The operating modes of general load modes include constant current, constant resistance, and constant power modes. In the constant current and constant power operation modes, users can program the power factor (PF) or peak factor (CF), or both. In the constant resistance operation mode, the PF value remains constant at 1.

The range of PF values may be limited by the set CF value (as shown in Figure 1). In addition, in the definition of the 63800 series, if the set PF is positive, it represents the current lead voltage; On the contrary, when PF is set to negative, it means that the current lags behind the voltage. (See the figure below)

Figure 1: CF vs. PF control range

CF SUB>I /SUB> = I peak / I rms

PF = True power / Apparent power

　　Rectification load mode

The load capacity of 63800 series AC/DC electronic loads can be widely applied to simulate nonlinear rectifier load testing. There are three modes available for simulating rectifier loads - RLC, constant power (CP), and surge current (Inrush Current) modes.

Figure 2 shows a typical circuit of bridge rectifier. In RLC mode, users can simulate the behavior of the actual test object 100% by setting the RLC value. Figures 3 and 4 respectively show measurements taken through actual passive loads (resistance, inductance, capacitance) and using RLC load mode. Figure 5 shows the waveform obtained in constant current mode.

Figure 2: Typical bridge rectifier circuit

In order to simulate surge currents (as shown in Figure 6), the 63800 series has a surge current mode that allows users to set different starting angles for surge currents, saving them a lot of time when measuring surge currents.

Figure 3: Actual RLC Circuit Diagram 4: Simulated RLC Mode

Figure 5: Constant current mode Figure 6: Surge current mode

　　DC load simulation

The 63800 DC load simulation includes four load modes: constant current, constant resistance, constant voltage, and constant power modes, as described below.

The constant current, constant resistance, and constant power modes can be used for power supply testing. As for battery chargers, the constant voltage mode can be used to help check their current adjustment.

The 63800 series DC rectifier load mode can be used to test the primary A/D of UPS. The DC rectification load mode of this * makes the 63800 an ideal load for UPS, fuel cell, PV module/array, and battery testing.

　　Diverse measurement functions

The 63800 series AC/DC electronic load has a built-in 16 bit precision measurement circuit to measure steady-state and transient responses. The measurement items include voltage root mean square value (Vrms), current root mean square value (Arms), real power (P), apparent power (S), virtual power (Q), peak factor (CF), power factor (PF), total harmonic distortion rate (THDv) of voltage, and positive and negative peak currents (± Ipeak).

In addition to these measured values, there are also two analog outputs, voltage and current, which facilitate users to provide monitoring voltage and current waveforms through an oscilloscope.

　　Time measurement

Time measurement is quite important for many products, such as UPS, circuit breakers, and fuses. The 63800 series AC/DC loads also provide * time measurement function to measure the tripping time of fuses and circuit breakers or the transfer time of Off line UPS.

Figure 7: Off Line UPS Conversion Time

　　Automatic Bandwidth Adjustment (ABA)

When the test object has a large output impedance, such as a generator, without automatic bandwidth adjustment function, the current waveform will be unstable, as shown in Figure 8. In most cases, the load current will oscillate and affect the accuracy of the test results.

Figure 8: Fixed bandwidth Figure 9: Automatic bandwidth adjustment

Note 1: A test current will be programmed prior the actual loading defined by user for impedance detection.

　　Parallel/three-phase control

The 63800 series provides multiple parallel, three-phase, and parallel three-phase functions, allowing users to perform testing applications on higher power or three-phase AC power sources. Among them, different types of loads in the 63800 series can also be connected in parallel or in three-phase configuration, which allows for more flexible and elastic use of 63800 series AC electronic loads to save costs.