CN207603237U - A kind of charge protection device of DC charging unit - Google Patents

Abstract

The utility model discloses a kind of charge protection device of DC charging unit, including MCU module；The MCU module is connect with current conversion module, communication module, protection module, analog input module；The current conversion module includes sequentially connected input filter circuit, AC/DC converters, output filter circuit.The utility model current conversion module is configured with AC/DC converters, can realize the two-way flow of energy, not only embodies the transformer characteristics of AC/DC, but also the inversion transformer characteristics of also DC/AC, really embodies " green energy transformation "；Communication module is configured, can realize remotely to the management of device and setting；It is configured with protection module so that there is high reliability and safety when device uses.

Description

A kind of charge protection device of DC charging unit

Technical field

The utility model is related to a kind of charge protection devices of DC charging unit.

Background technology

Scape technology

DC charging unit is widely used in waterpower, thermal power plant, all kinds of substations and other using DC equipment User, with China's industrial or agricultural and the development of Process of Urbanization Construction, electricity consumption is presented rapid growth situation, straight-flow system miniaturization, High reliability, it is non-maintaining will be following developing direction.Equipment as receiving with dividing distribution network electric energy, DC charging unit should Dosage is big, applied widely, and key player is play in electric system.

At present, with the raising of grid supply quality and automatization level, for wanting for substation's power distribution station power distribution equipment Ask also higher and higher.Transforming plant DC power-supply system is as the independent current source in power plant and substation, not by Alternating Current Power Supply It influences, in the case of full factory or whole station dead electricity, remains to control, signal, measurement and relay protection, automatic device, operation machine Structure motor, breaker Electromagnetically-operating switching-on mechanism, emergency lighting etc. provide reliable and stable power supply.Therefore DC power system pair Reliable and stable operation, the excision of quick accident and the recovery of electric system are of crucial importance.At present, lithium battery is due to it Small, light weight, and it is environmentally protective the features such as, be widely used in DC power system.And DC charging unit It is exactly the charging modes in order to provide reliable safety to DC power system, is dedicated to preferably serving other direct current electricity consumptions A product of equipment.

Meanwhile on the one hand because of charging unit to the harmonic pollution problems of power grid.Such as unreasonable control rectification, in net side Serious current distortion will be generated, is injected to power grid abundant idle, power grid is caused seriously to pollute so that under power grid power quality Drop.On the other hand because of power battery intrinsic charge characteristic in itself, it is desirable that charging equipment has to comply in charging process The charge characteristic of battery, it is impossible to arbitrarily charging in itself.It not only results in battery life in this way to greatly shorten, it is also possible to damage electricity Pond ontology.This requires with a kind of intelligentized charging unit, can implement effective control to each charging stage of battery System so that charge characteristic meets battery intrinsic characteristic in itself, meets the growth requirement of intelligent grid.

Invention content

Technical problem to be solved in the utility model is, in view of the shortcomings of the prior art, providing a kind of DC charging unit Charge protection device, improve reliability and the safety of charging unit.

In order to solve the above technical problems, technical solution is used by the utility model：A kind of DC charging unit fills Electrical protective device, which is characterized in that including MCU module；The MCU module and current conversion module, communication module, protection mould Block, analog input module connection；The current conversion module includes sequentially connected input filter circuit, AC/DC converters, defeated Go out filter circuit.

Current rectifying and wave filtering circuit is further connected between the input filter circuit and the AC/DC converters.

The current rectifying and wave filtering circuit is industrial frequency rectifying circuit.

The output filter circuit includes sequentially connected high-frequency rectification circuit, LC filter circuits and EMI filter circuit.

The input filter circuit output terminal, output filter circuit output terminal, AC/DC converters connect with detection circuit It connects；The detection circuit is connect with controller.

Compared with prior art, it is had the beneficial effect that possessed by the utility model：The utility model current conversion module is matched AC/DC converters are equipped with, can realize the two-way flow of energy, not only embody the transformer characteristics of AC/DC, but also also have The inversion transformer characteristics of DC/AC really embody " green energy transformation "；Communication module is configured, can realize remotely to device Management and setting；Protection module is configured with, improves reliability and the safety of charhing unit.

Description of the drawings

Fig. 1 is the utility model DC charging cellular construction block diagram；

Fig. 2 is the utility model current conversion module schematic diagram；

Fig. 3 is the utility model current conversion module hardware structure diagram；

Fig. 4 is the utility model charhing unit charging voltage/current curve diagram；

Fig. 5 is the utility model overvoltage protection logic chart；

Fig. 6 is the utility model current limliting output protection logic chart；

Fig. 7 is the utility model short-circuit protection logic chart；

Fig. 8 is the utility model overheat protector logic chart.

Specific embodiment

As shown in Figure 1, the utility model charhing unit functions are as follows：

1st, MCU module

The MCU module of device uses the high-performance 32-bit dsp chip that Texas Instrument provides, and data processing function is powerful, branch Hold at least 16 road analog acquisitions and 32 road programmable digital amounts；The core of whole system operation, controls charhing unit Stop and start, feeder line information collection, charging unit throwing move back, information instruction, historical data displaying and its a distant place communication etc..

2nd, analog input module

Unit simulation input module major function for acquisition AC-input voltage, DC output voltage, DC bus-bar voltage, Load current, battery current.It selects 12 bit AD samples, and precision is higher, and the data of acquisition are as the foundation for protecting judgement.

3rd, communication module

Major function is the data for acquiring device and outputs action message and produce, and supports RS485 serial communications and TCP/ IP Industrial Ethernet mouth communicates.

4th, current conversion module

Current conversion module be by power grid AC rectification be the direct current with rated voltage, output a part to store Battery charges, and another part gives control load power supply.

5th, protection module

Major function provides output over-voltage protection, current limliting output protection, short-circuit protection, overheat protector for device.

DC charging unit should be able to ensure to carry out lithium battery rationally adequately charging, and can effectively prevent pair It is overcharged, and current conversion module operation principle is as shown in Figure 2 and Figure 3.

（1）Main circuit

Main circuit is converted by ac filter rectification, DC/DC and the circuits such as filtering exports form, and is divided into following several function parts Point：

Input filter：Circuit includes low-pass filtering, surge voltage inhibits etc., which filters out the clutter in power grid, and hinders Only the clutter of the machine feeds back to input power grid.The part is also input port.

Rectifying and wave-filtering：It is smooth DC voltage by the direct rectification of filtered alternating current, for DC-dc conversion（DC/ DC is converted）.

DC/DC is converted：The partial circuit is made of Power Exchange and high-frequency rectification two parts.After the pre- rectification of AC network DC power supply be transformed to the DC power supply for meeting power engineering requirement.

Filtering output：DC voltage after DC/DC is converted meets satisfactory DC voltage through secondary filtering acquisition It charges to accumulator.The part is also output port.

（2）Control circuit

The control that control circuit realizes it key link is needed during the entire process of voltage transformation.Control mode uses Software-controlled manner based on DSP, by detection circuit, amplifying circuit is compared detection signal, amplifies, straight so as to control Translation circuit is flowed, pulse frequency is adjusted or pulsewidth plays the role of stabilizing the output voltage.Simultaneously according to detection data, need to master Circuit carries out the protection of voltage and current and temperature.

（3）Detection circuit

Detection circuit is that output circuit is used, so as to obtain the related data of reflection charge power supply operating status, Control circuit is fed back information to, the work of main circuit is controlled or regulated by control circuit.

The working method of current conversion module can be divided into following three kinds:

（1）Normal charging condition：Under normal condition, alternating current is converted to dc bus and connects load by current conversion module Required DC power supply, also the accumulator group of its band does not provide floating current.

（2）State is rushed in timing：Management to accumulator group for convenience, central controller can also be according to presetting Setting control current conversion module accumulator is rushed.

（3）It charges after battery discharge：After accumulator carries out the electric discharge of verification property or exchange has a power failure, after battery discharging, electricity Stream modular converter can charge to accumulator automatically according to remaining battery capacity or charging current.After battery discharge, charging The current/voltage curve graph that unit charges to it is as shown in Figure 4.

When initial, because the residual capacity of accumulator is small, the larger satisfaction of charging current turns to rush criterion, and charhing unit is to electric power storage Pond carries out constant current and rushes, at this point, battery charging current is constant, voltage constantly rises；Voltage is rushed when battery tension reaches When, current conversion module is converted to constant pressure and rushes（Such as figure 4 above A points）, at this point, battery tension is constant, electric current constantly declines, When charging current is less than predetermined definite value（Such as figure 4 above B points）, start timing, after 180 minutes（Timing time can be set）It is i.e. full After foot turns floating charge criterion, current conversion module turns floating charge（Such as figure 4 above C points）, then into normal operating conditions.

The utility model defencive function is as follows：

Output over-voltage protection is as shown in figure 5, any one phase voltage of output DC voltage is more than setting value Udz, and be more than Be delayed definite value T1, and power conversion module is automatically locked, and module fault indicator is bright, and charhing unit automatically exits from work.The part Logic can realize switching and fixed value adjusting by the soft pressing plate of device.

Current limliting output protection as shown in fig. 6, when any one phase value of output current three-phase is more than 1.05 times of rated current, and And more than delay definite value T2, power conversion module is automatically locked, and module fault indicator is bright, and charhing unit automatically exits from work. The part logic can realize switching and fixed value adjusting by the soft pressing plate of device.

Short-circuit protection principle is as shown in fig. 7, when three-phase electricity flow valuve is more than short circuit current setting valve, the soft pressing plate of short-circuit protection moves Make, by being delayed, output voltage is pulled down to zero by T3, and limiting short-circuit current is less than the 15% of output-current rating.

Overheat protector principle is as shown in figure 8, when temperature sensor detection temperature is more than overheat protector setting valve, overheat protector Soft pressing plate control fan rotation cooling, while be delayed by T4, protection act tripping, charhing unit exits work.When temperature passes Sensor detects that temperature meets charhing unit operating temperature, can start state of resuming work automatically again.

Claims (5)

1. a kind of charge protection device of DC charging unit, which is characterized in that including MCU module；The MCU module and electric current Modular converter, communication module, protection module, analog input module connection；The current conversion module includes sequentially connected defeated Enter filter circuit, AC/DC converters, output filter circuit.

2. the charge protection device of DC charging unit according to claim 1, which is characterized in that the input filter electricity Current rectifying and wave filtering circuit is further connected between road and the AC/DC converters.

3. the charge protection device of DC charging unit according to claim 2, which is characterized in that the rectifying and wave-filtering electricity Road is industrial frequency rectifying circuit.

4. the charge protection device of DC charging unit according to claim 1, which is characterized in that the output filtered electrical Road includes sequentially connected high-frequency rectification circuit, LC filter circuits and EMI filter circuit.

5. the charge protection device of DC charging unit according to claim 1, which is characterized in that the input filter electricity Road output terminal, output filter circuit output terminal, AC/DC converters are connect with detection circuit；The detection circuit and controller Connection.