1. Introduction

In occasions such as power plant, electric substation and UPS systems, crucial equipment and emergency facilities should be granted with an all-the-time power supply. Hence batteries are the only power supply and the priority equipment of 24-hour power supply in case of AC power failure or other accidents.

However, the properties of batteries and the currently limited techniques disable their functions of equalizing charge, accurate on-line monitoring and activation of poor batteries. All those hidden dangers loom large to the operation of batteries. The cells with designed service life of 15-20 years may only sustain 3-5 years application. Devastating waste in resources, production costs and environmental pollution have been caused by the short-lived batteries.

Only by maintaining the batteries’ stability, grasping their actual internal resistance, capacity, activating some poor batteries in a timely manner and enhancing the online operating batteries’ reliability can we really realize the goals of obtaining timely emergency power supply, ensuring a sound operation of instruments and networks in addition to prolonging cell’s service life, saving more investment costs and reducing environmental pollution.

2. Operation Status of Batteries
Because of the importance of back-up power, most of the grid companies and big players in power consumption are applying the combination of one set of DC power supply and two sets of batteries in the mode of “double sets of chargeable batteries and double sets of gird power”. While for some power plants’ DC system in machine units, the mode of “double sets of gird power and tertiary sets of chargeable batteries” is advised to be applied in main line connection, reflecting the top priority of DC system and batteries in power industry. However, there are still some shortcomings existing in batteries’ operation.

 

Technically, there are some defects in the operation of existing batteries.
1. Charging serial-connected batteries online with chargers can not ensure the charging balance of each battery monomer in the batteries. Changing terminal voltage (higher or lower) causes the overcharged or undercharged status of batteries. Overcharge will decrease the capacity of batteries rapidly and long-term undercharged status will result in an increased internal resistance.

2. Traditional batteries adopt the charging curve of periodical vigorous charging (720h) to regain poor batteries capacity in charging compensation. However, this charging method would always overcharge those fine batteries in the same batteries.

 

Failure of batteries in balanced charging has always been a hidden danger for power operation.
1. It is common that the batteries’ average service life dramatically shortens due to overcharging or undercharging of a battery monomer. Hence batteries with designed service life of fifteen to twenty years are eliminated in three to five years because of their insufficient capacity and increased internal resistance.

2. The overall performance of serial-connected batteries is determined by the poorest cell. The battery monomer will impose danger on all the batteries with its excessively low voltage, small capacity and high internal resistance. If timely measures are not taken to rectify such situation, accidents may occur due to the failed power supply at any time.

 

The online activation may not be realized, while the batteries’ capacity is regularly checked.

A battery monomer’s performance is decided by its terminal voltage, internal resistance, capacity and electromotive force, etc. Hence performance judgment should be made based on the above parameters. Traditional battery inspection device only inspects the terminal voltage of each cell of batteries and traditional internal resistance tester can only test the internal resistance of each cell of batteries, so are those products designed for capacity checking and activation. However, such products only judge the batteries from a single and partial perspective.

3. Product Introduction

LBE200 The Storage Battery Online Performance Balance System is a valuable supplement to the DC system recharger, solving the discrepancy problem of battery cell performance in the operation of batteries and prolonging the service lift for two times of the previous one.

 

It can be seen as providing every battery with a recharger. Through the advanced microcomputer control technology and electric power technology, the on-line balancing control of cell of batteries can be conducted automatically so as to maintain the terminal voltage, storage capacity and internal resistance within the balancing range, avoid the overcharge or undercharge and conduct on-line recharging and activation to the battery cells with weak performance. This product can replace the battery inspection device or online battery internal resistance tester, which will exert a profound effect on investment reduction, energy saving and emission reduction, ecological construction and realization of sustainable economic development.

This system is composed of monitoring module, balance adjusting unit, cell measuring unit and cell activating unit.

 

 

■ Monitoring module: computer analysis, comprehensive management and communication.

■ Balancing and adjusting module: composed of adjusting control and power part, balancing the batteries’ operation through balance control under the assistance from monitoring module.

■ Measuring unit: measuring each battery monomer’s terminal voltage, internal resistance, capacity, etc.

■ Activating unit: adopting patented digital power supply to eliminate sulfate crystal on the polar plate.

The system can operate when the power is on. Balance degree should be calculated according to the data of cell voltage collected by cell measuring unit. Balance adjusting module will automatically adjust each battery monomer respectively when the balance degree excesses the designed value, until balance degree is within the specified range.

Schematic diagram of the system

 

4. Product Function
■ Online balancing function

LBE200 The Storage Battery Online Performance Balance System can balance every battery monomer’s operation, providing the working condition of the same voltage, internal resistance and capacity and avoiding rapid aging caused by overcharge or undercharge. Each battery monomer can be adjusted automatically (as well as manually adjusted by force) to conform the battery monomers’ performance and prolong their service life.

 

Comparison before and after the application of online balancing function

On April 27, 2007, the measured batteries balance degree (consistency) of 48V/200AH batteries was 10.4 after LBE 200 The Storage Battery Online Performance Balance System was applied in the central substation in the Electric Power Bureau of a certain city. On April 30, 2009, the second measurement of 48V/200AH batteries was taken after the LBE 200 The Storage Battery Online Performance Balance System was applied, and the batteries balance degree (consistency) rose to 1.1, which proves the balancing effect.

            

Data before application of equipment  data after application of equipment         operation report of users

■ Function of online activation

LBE200 The Storage Battery Online Performance Balance System can activate the battery monomer with poor performance online to avoid the sulphation resulted from long-time floating charge. This application can double the batteries’ service life and reduce environmental pollution, contributing to social profits and environmental protection.

Comparison pictures of battery after LBE200 battery activation technology is applied

       

         Left picture                         Right picture

Left picture: the first picture displays the massive sulfate crystallization ( (polar plate of lead-acid battery). And the discharge time only lasts for about 13min when full discharge test was carried out.

Right picture: this is the picture of the same polar plate, but the plate has been installed with LBE 200 The Storage Battery Online Performance Balance System for 18 days. It can be shown that the sulfate crystallization has been eliminated, and the discharge time lasted for 33min, meaning that discharge capacity increases by 250%.

Micrograph of comparison before and after the battery-activation-technique application is as shown

 

           

          Left picture                               Right picture

Left picture: battery plate is massively covered by lead sulfate (lead sulfate crystal micrograph).

Right picture: lead sulfate crystal has been cleared away by activation technology and the active material of battery polar plate has been revealed after the application of LBE200 The Storage Battery Online Performance Balance System .

No.	LBE200 The Storage Battery Online Performance Balance System	Battery inspection device	Online inspection device of  internal resistance of battery	Battery activation device
1	Balance each battery monomer’s voltage, internal resistance and capacity on line to avoid overcharge or undercharge caused by OVP or UVP of battery monomer, thus doubling cells’ service life.	No	No	No
2	Activate the battery with weak performance online to prolong its service life.	No	No	Activation offline
3	Test internal resistance of each battery online	No	Yes	No
4	Test capacity of each battery monomer online	No	No	No
5	Test voltage of each battery monomer on line	Yes	Yes	No
6	Before the application of LBE200 The Storage Battery Online Performance Balance System, the whole batteries should be replaced due to the performance inconsistence of new and old cells. However, after the application, each cell can be automatically adjusted to consistent performance, therefore, only the cell which is out of service, instead of the whole batteries, needs to be replaced when replacement is required due to physical or chemical performance of some battery cells, thus consumedly reducing the operation cost.	No	No	No

5. Core advantages
■ LBE200 The Storage Battery Online Performance Balance System adopts 32-bit SCM with technical grade and high performance, 12-bit A/D and Chinese character LCD, which can measure and balance 112 battery monomers. It can give an alarm in case of abnormity of voltage, internal resistance or capacity, conduct online measurement of terminal voltage, internal resistance and capacity accurately and provide operation data of each cell.

■ The system can calculate balance degree according to the data of cell voltage collected by cell measuring unit. Balance adjusting module will automatically adjust each battery monomer respectively when the balance degree excesses the set value, until balance degree is within the specified range.

■ Compute intelligent detection and control system can conduct voltage and current A/D test with stable charging and online balance of each battery monomer.

■ It can automatically control efficient frequency converted pulse through various means, automatically measure the ambient temperature and offset voltage parameter. Through pre-charge with the measurement of capacity, mischarge will be avoided. The detection of voltage type with accuracy can successfully avoid mischarging, transposition, short circuit, over-current and over-voltage, over-heat and overtime so as to prevent battery from rapid aging caused by overcharging or undercharging and prolong cell service life.

■ Activate poor and aged cell on line to restore its capacity and prolong its service life, which ensures the safe and stable operation of batteries, avoid the damage to batteries caused by one invalid battery monomer, reduce scrape rate, save investment cost and reduce emission.

■ Measure the voltage, internal resistance and capacity of online charged batteries with accuracy. Cell measuring unit can measure each battery monomer’s terminal voltage, internal resistance and capacity. Utilize special method to produce instantaneous load, and then calculate cell internal resistance through instantaneous voltage drop and load current. The device will conduct measurement of internal resistance and capacity automatically (or through manual operation) every half month (360h).

■ LBE200 The Storage Battery Online Performance Balance System is fitted with RS485 communication interface and MODENBUS protocol specification to realize remote intelligent management.

VI. Product parameter and dimension
1. DC rated operating voltage: DC384V,DC220V,DC192V,DC110V,DC48V,DC24V;

2. Number of battery pack that can be balanced: 2-192;

3. Rated capacity of battery that can be balanced: 20-4000Ah;

4. Voltage of battery monomer that can be balanced: 2V, 4V, 6V, 12V;

5. Measurement precision of voltage of battery monomer: ≤±0.1%;

6. Measurement precision of battery voltage: ≤±0.5%;

7: Online testing precision of battery capacity: ≤5%;

8: Online testing precision of battery internal resistance: ≤5%;

9. Mean time between failure (MTBF): no less than 80000h under normal operating environment;

10: Alarm precision: ±2% of the setting value;

11. A/D conversion error: no more than 0.1;

12. Degree of unbalance: <0.5%;

13. Noise: <45dB.

Type A/ Vertical	Type B/Horizontal	Type C/ Cabinet-type
Applicable for the following battery system, with independent installation applied	Applicable for the following battery system, with panel assembly applied	Applicable for the above battery system, with independent installation applied

7. Product classification
Standard type

1. 192 battery monomers can be measured and balanced.

2. RS485 Communication is adopted for the battery measurement & balancing part and if there is a failure in this part, the communication failure will be reported by the monitoring part.

3. Balance operation will be prohibited by system when alarm occurs.

4. The degree of balance and the numbering of battery to be balanced are monitored and displayed in real time.

Enhanced type

1. 192 battery monomers can be measured and balanced.

2. The capacity of the battery monomers in batteries is tested online;

3. The internal resistance of the battery monomers in batteries is tested accurately online;

4. RS485 Communication is adopted for both the monitoring part and battery measurement & balancing part which compose the equipment control system and if there is a failure in the balancing part, the communication failure will be reported by the monitoring part.

5. Balance operation will be prohibited by system when alarm occurs.

6. The degree of balance and the numbering of battery to be balanced are monitored and displayed in real time.

High-end type
1. 192 battery monomers can be measured and balanced.

2. The poor and aged battery monomers in the batteries can be activated online with the capacity recovered;

 

3. The capacity of the battery monomers in batteries is tested online;

 

4. The internal resistance of the battery monomers in batteries is tested accurately online;

 

5. RS485 Communication is adopted for both the monitoring part and battery measurement & balancing part which compose the equipment control system and if there is a failure in the balancing part, the communication failure will be reported by the monitoring part.

 

6. Balance operation will be prohibited by system when alarm occurs.

 

7. The degree of balance and the numbering of battery to be balanced are monitored and real-time displayed.

 

8. Model instruction and options
Model instruction

 

Product model options

Functions	Standard type	Enhanced type	High-end type
	LBE200-DS	LBE200-DE	LBE200-DH
Voltage inspection and display of battery monomer	√	√	√
Measurement and display of the voltage of entire battery pack	√	√	√
Measurement of charge and discharge current of battery pack	√	√	√
Settings of system alarm parameters	√	√	√
Alarm display of poor and aged cells and previous alarm records query	√	√	√
Protection	√	√	√
Online voltage balance of battery monomers	√	√	√
Online internal resistance measurement of battery monomers		√	√
Online capacity measurement of battery monomers		√	√
Online activation of battery monomers			√
RS485 Interface and protocol	√	√	√
Selection of product shape	A or B	A or B or C	A or B or C