The storage battery pack is the core of the substation DC system, which is used to ensure the power supply for various DC loads and emergency lighting in the event of AC power failure in the substation. Conducting regular discharge capacity tests on battery packs in accordance with regulations is an effective way to accurately verify the performance of battery packs. The FDT-220/110 DC System Comprehensive Tester developed by Wuhan Haomai Electric Power integrates battery pack discharge, charger ripple coefficient test, and voltage/current stabilization accuracy characteristic test. It can automatically and continuously regulate the discharge current to achieve constant-current discharge at a set value.

△ FDT-220/110 DC System Comprehensive Tester

During the discharge process, when the battery pack terminal voltage or the single-cell voltage (with a supporting wired or wireless battery test system) drops to the set lower limit value, or the set discharge time is reached, the FDT-220/110 DC System Comprehensive Tester will automatically stop discharging to avoid battery damage. During discharge, it monitors the voltage of each battery cell, displays the discharge current, voltage, time and discharge curve in real time, and saves the data in the device, which can be uploaded to a PC via a USB flash drive. The device is equipped with built-in *.xls report generation software, which enables query, analysis and report output of discharge data. During charging and long-term operation, it monitors the voltage of each battery cell and gives an alarm in a timely manner when a battery is damaged.

Test Operation Steps

Battery Pack Discharge Test: Enter the discharge test interface, set the discharge parameters, and click Start Discharge to conduct the test. Initially, the discharge current will increase to 95% of the set value, and then slowly rise to the set value. During the discharge process, if the battery pack terminal voltage and single-cell voltage do not reach their respective lower limits, the device will keep running normally.

△ Parameter Setting Interface

△ Single-cell Voltage Bar Chart

△ Charging Characteristic Curve

Charge Detection Test: Enter the charge detection test interface, set the test parameters, and click the Start Charging button to conduct the test, with real-time monitoring of the battery pack terminal voltage and single-cell voltage. This test does not require closing the air switch; the charging voltage is displayed normally, and the charging current is displayed as 0.

Charger Characteristic Test: Check the option if a voltage regulator is to be used when setting charging parameters, then select the corresponding voltage stabilization accuracy, charging characteristic and current stabilization accuracy for the test.

△ Charger Characteristic Test Parameter Setting

△ Charger Voltage Stabilization Accuracy Test

DC Ripple Detection Test: Enter the test start interface and click Start Test to observe the ripple waveform of the current charger DC voltage.

△ DC Ripple Monitoring

If the parameter saving fails when setting the discharge test and charger characteristic test, please close the previously suspended test before resetting.

Conduct the test according to the above operations. The air switch will be automatically turned off after the test is completed. If the air switch trips during the discharge test, it may be because the single-cell voltage or the battery pack terminal voltage has reached the set lower limit, and the cause of the air switch tripping will pop up on the screen at the same time. If the test is interrupted due to the single-cell voltage reaching the lower limit, the device will display the battery cell with low voltage, facilitating quick identification of the battery with insufficient capacity.