Lithium battery forklift, relying on energy storage as power supply, a set of circuit design in recharge and discharge area, once produce fault in the circuit, then the battery forklift will increase output current, use a shorter time to natural, charging, too, the design is unreasonable, charge is not too much into or current input, too, booster discharge circuit adopts double closed loop control method, with the controller output voltage as the feedback signal in closed loop control.
A given output voltage Vref and compare with the actual output voltage error, PI regulator to obtain current loop given current Iref.
Given the current Iref get current error compared with the actual controller output current, after PI regulator to drive waveforms PWM wave controller.
Waveform after isolation drive control IGBT open and shut off, carrying out the transformation of DC/DC booster, real-time change duty ratios adjust controller output current to control the output voltage reach the goal;
Electric lift trucks in the lithium battery charging system is designed for the circuit of power transformer can use old set each enough idle, for a short time for lithium battery charging, slightly less than charging power (power allows
24 v or 12 v, 10 a)
, the secondary voltage should be 18 ~ 22 v.
Due to the charging current for pulse current, such already can improve the charging efficiency, also can reduce the temperature rise of transformer.
VD1 ~ VD4 in circuit of ac voltage rectifier, form a pulsating direct current.
Appropriate adjustments to RI to control the charging voltage of CZ l to achieve the purpose of changing VT1 emitter voltage.
VT1 base potential with pulsating voltage change, when it is lower than the emitter instantaneous voltage, VT1 conduction.
The pressure drop of R4 made VT2 conduction.
And the R5, R6, partial pressure of voltage keep on state V diode VD5 trigger ChanXiangJing asked tube conduction, charging pulse through the lithium-ion battery pack.
When the pulse electric current through the zero V shut off.
By adjusting the RI to control each half cycle V conduction Angle, so as to change the average current value of the lithium battery.
When R1 to switch to the right end, charging an average current biggest;
The opposite is minimal.
When several or more forklift battery of lithium battery series, the main loop current is, for example.
Each series battery to have a balanced bypass, BTi is monomer battery, Si mosfets, inductance Li is energy storage element.
Si, Li Mi, Di constitute a shunt module.
In a charging cycle, the working process of the circuit is divided into two stages: voltage test phase (
Time for Tv)
And filling stages (
Time for Tc)
In voltage detection phase, balanced bypass circuit doesn't work, the main power for charging the battery pack, detection of single battery voltage of the battery pack at the same time, and according to the control algorithm to compute MOSFET duty ratio.
In the filling stage, the bypass triggered MOSFET is controlled by the calculation of the duty ratios of switch state, are filling processing to the corresponding battery.
In this stage, flows through the current of each monomer battery is constantly changing, is also each are not identical.
Remove the connection on both ends of B1 M1, all bypass shunt modules are the same.
In both filling bypass, the diode to the single function of Di, all bypass module will be redundant moved upstream from the corresponding battery cells, and M1 is the extra power transferred to the downstream of the battery;
Shenzhen power supply co. , LTD is a professional committed to the power supply, energy storage power supply, emergency power supply, start the power supply in areas such as lithium battery system solutions provider, is located in the beautiful huacheng -
Shenzhen, the establishment of the company, marked the tractor formal presentation, amplification with independent brand of lithium battery at home and abroad to promote electric forklift, wind energy, electric cars and other industry capability of independent research and development has important strategic significance, the process of development, multiple battery research institutions at home and abroad exchanges and cooperation, constantly absorbing the world advanced technology, design and development, the scale expands unceasingly, the future for the forklift truck, car and so on various sections market pattern changes will have far-reaching influence, pioneered the green energy wise man.
More lithium battery forklift news: newshow.