Three Phase Closed I-P Links Energy Meter Test Bench
1. Brief Introduction:
three-phase stationary test bench is designed for testing three-phase energy meters accuracy below 0.2, especially for testing Closed I-P Links three-phase energy meters. Test bench can generate 3-phase voltage, 3-phase current and any power factor signal for tested meter, the reference meter’s accuracy is class 0.05(0.1).
2.Advantages:
a. DDS technology signal generator:
The signal generator adopts digital sine wave composing technology. The signal generator can trace the voltage phase and supply a dummy load to the tested meter by outputting adjustable current with different phase;
b. High efficiency D-Class current amplifier and voltage amplifier:
The equipment use PWM power amplifier(or we called D-Class amplifier), which is high efficiency (>85%) and very low heat consumption. The amplifier has protection circuit itself, it can avoid damage due to wrong connection or other manual operations. Current amplifier and shifter can output any current from 0.001A to 100A; Voltage amplifier can output any voltage from 50V to 450V;
c. DSP+MCU dual processor designed multifunction reference meter.
The reference meter use one DSP to sample the signal of three phase voltage and three phase current, it sample the voltage waveform and current waveform continuously, even there are harmonic exist in the waveform, the reference meter can also measure the voltage/current/power in dependable status; And other MCU is designed to display the tested result and receive input information.
d. DCS framework designed error calculator system.
The error calculator system is designed as DCS framework, every meter position has one isolated error calculator, error data is transferred from RS485 Bus, PC can receive every meter’s error data and then displayed it on the screen, the error calculator can receive signal which due to TTL / OC or Optical head output.
e. Can be controlled from keyboard or software.
The equipment has operated keyboard itself, the equipment can be operated form software and also it can be operated from keyboard. Without PC you can also test meter’s error.
3.Difference between Closed I-P Links and Open I-P Links:
When we test the Closed I-P Links energy meter, if the current for every meter is not isolated, current can transfer A to B or A to C or B to C from voltage wire. In order to avoid the current transfer from voltage wire, current for every meter should be isolated ,the connection diagram is shown as below：
When we test the Open I-P Links energy meter, the current for every meter can’t transfer A to B or A to C or B to C from voltage wire, because the voltage wire and current circuit is not connected. The connection diagram is shown as below：
4. Technical specification:
Specification of phantom load power source:
Power and consumption:
Power supply: 1P2W 220V/240V ±10%, 50Hz or 60Hz; Or (3P4W 3x220V/240V ±10%) Max consumption: 1800VA (8 meter positions)
Current source:
Output current: 3×0.001A-3×100A
Adjusting resolution: 0.01% (min. 0.0001A)
Power factor: 0~3600; resolution: 0.10
Output frequency: 45Hz~65Hz;
THD(sine wave output): <0.8% Stability of current during sine wave output: 0.05% (180s)
Output wave: sine wave
2-21 harmonic wave, total should be less than 40%
Odd harmonic waveform
Sub harmonic waveform
Output capacity: 50VA per meter position
Voltage source:
Load: The Load can be resistor / inductive / capacitive(<4uF)
Adjusting resolution: 0.01% (min. 0.1V)
Output frequency: 45Hz~65Hz;
THD (sine wave output): <0.8%
Voltage stability of power source during sine wave output: 0.05% (180s)
Output wave: sine wave 2-21 harmonic wave, total should be less than 40%
Output capacity: 20VA per meter position
Reference Meter:
Power and consumption:
Power supply: 1P2W 220V/240V ±10%, 50Hz or 60Hz;
Max consumption: 30VA
Voltage input: 3×30V-3×300V (AC)
Current input: 3×0.001A-3×100A (AC)
Accuracy:
Active power: 0.05% (PF>0.5)
Reactive power: 0.1% (PF>0.5)
Warm up time: < 2 minutes
Dimension: 482mm X 380mm X 140mm
Weight: <7.5Kg
Isolation transformer:
Power and consumption:
Power supply: 1P2W 220V/240V ±10%, 50Hz or 60Hz;
Max consumption: 10VA
Current input: 0.01A-100A (AC)
Accuracy: 0.02%
Warm up time: < 5S
Dimension: 220mm X 220mm X 220mm
Weight: <18Kg
Error Calculator:
Impulse of tested meter could be: TTL / OC / Optical head
Max frequency of impulse could be: 200Hz
Error display range: 0.001%-99.99%
5. About software:
a. Error test;
b. Starting UP test;
c. Creep test;
d. Deviation test;
e. Harmonic Influence test;
f. Voltage variation Influence test;
g. Frequency variation Influence test;
h. 24H error variation;
i. Report output;
j. Error data to Excel table. | 
