CN115693637A - Direct-current power supply grid-connected device, system and method - Google Patents
Direct-current power supply grid-connected device, system and method Download PDFInfo
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- CN115693637A CN115693637A CN202211423162.7A CN202211423162A CN115693637A CN 115693637 A CN115693637 A CN 115693637A CN 202211423162 A CN202211423162 A CN 202211423162A CN 115693637 A CN115693637 A CN 115693637A
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Abstract
The invention aims to provide a direct-current power supply grid-connected device, a direct-current power supply grid-connected system and a direct-current power supply grid-connected method, which greatly improve the grid-connected compatibility. The invention relates to a direct current power supply grid-connected device, which comprises a voltage acquisition module, a current acquisition module and a voltage regulation module; the voltage acquisition module is used for acquiring the output voltage of the direct-current power supply and outputting the acquired voltage to the voltage regulation module after the acquired voltage is divided by a set proportion; the current acquisition module is used for acquiring the output current of the direct current power supply, converting the acquired current into voltage, combining the voltage with the voltage output by the voltage acquisition module, outputting the voltage to the voltage regulation module and regulating the voltage division proportion of the voltage acquisition module; the voltage adjusting module is used for adjusting the electric energy transmitted to the voltage output end by the direct current power supply transformer according to the voltages of the voltage collecting module and the current collecting module so as to adjust the output voltage of the direct current power supply. The invention is suitable for the power supply grid connection of the direct current power supply.
Description
Technical Field
The invention relates to the field of direct-current power supply grid-connected power supply, in particular to a direct-current power supply grid-connected device, system and method.
Background
At present, 220V or 380V alternating current is adopted for power supply in a power supply grid, but more than eighty percent of electric equipment can convert alternating current into low-voltage direct current for reuse. For example: industrial production lines, medical instruments, communication equipment, electric vehicles, home appliances, digital products, and other electronic products using storage batteries all use direct current.
Taking communication equipment as an example, a communication equipment room generally adopts 48V direct current as a power supply bus of the whole room, and all communication equipment in the room adopts 48V direct current for power supply. A high-power direct-current power supply is arranged in a machine room to convert 220V alternating-current mains supply into 48V direct current, and because the total power of communication equipment in the machine room is large, one direct-current power supply cannot bear all power supplies of the machine room, a plurality of direct-current power supplies are usually adopted to be connected in a grid mode to supply power to the machine room.
The current DC voltage output by the DC power supply is stable and constant as long as the load current does not exceed the rated current of the power supply (I in FIG. 1) 0 ) The voltage value is fixed. The output voltage and current relationship of the power supply is shown in fig. 1.
The condition of grid connection of direct current power supply output is that the output voltages are required to be equal, but even if the power supplies are of the same specification and the same model, the output voltage of each power supply is deviated. The small voltage deviation among individuals can directly cause unbalanced load of the grid-connected power supply and even abnormal work.
The existing solution at present is to design a current sharing control circuit inside the power supply. The current-sharing control circuit in each power supply can finely adjust the output voltage, so that the output current of the power supply is controlled to achieve the purpose of sharing the load. The current-sharing control circuit collects the output current of the power supply and reflects the output current onto the current-sharing bus in a voltage mode. And meanwhile, the voltage of the bus is also collected to control the output voltage of the power supply. As shown in FIG. 2, power supply 1 to power supply N are tied in (+ VOUT and-VOUT) to supply power to the load; the ISHARE + and ISHARE-are current-sharing buses, and all power source current-sharing buses are connected in parallel. The working mode is as follows: if the output current of the power supply 1 is large (with heavy load), the voltage of the ISHARE + of the power supply 1 will rise, and other power supplies sensing the rise of the voltage of the ISHARE + of the bus will rise their output voltage, thereby sharing the load of the power supply 1. Thereby achieving the purpose of current sharing.
However, in the existing scheme, each power supply needs to be provided with a current-sharing bus at the output end, and the current-sharing buses need to be connected in parallel separately. In practical application, the power supply needs to define the current-sharing bus pin in the output connector separately, and the system needs to design the connection line of the parallel current-sharing bus. In some complex systems, the difficulty of routing is increased; and the system must adopt the power supply with the same model specification to carry out grid connection, and the compatibility is poor.
Disclosure of Invention
The invention aims to provide a direct-current power supply grid-connected device, a direct-current power supply grid-connected system and a direct-current power supply grid-connected method, which do not need the design of a current-sharing bus, simplify the grid-connected connection mode, reduce the wiring of a direct-current power supply system and greatly improve the compatibility of direct-current power supply grid connection.
The invention adopts the following technical scheme to realize the aim, and the direct-current power supply grid-connected device comprises a voltage acquisition module, a current acquisition module and a voltage regulation module;
the voltage acquisition module is used for acquiring the output voltage of the direct-current power supply and outputting the acquired voltage to the voltage regulation module after the voltage is divided by a set proportion;
the current acquisition module is used for acquiring the output current of the direct current power supply, converting the acquired current into voltage, combining the voltage with the voltage output by the voltage acquisition module, outputting the voltage to the voltage regulation module and regulating the voltage division proportion of the voltage acquisition module;
and the voltage regulating module is used for regulating the electric energy transmitted to the voltage output end by the power converter of the direct current power supply according to the voltages of the voltage acquisition module and the current acquisition module so as to regulate the output voltage of the direct current power supply.
Further, the voltage regulation module comprises a first operational amplifier, an optical coupler and a voltage regulation chip, wherein the reverse input end of the first operational amplifier is respectively connected with the voltage collection module and the current collection module, the forward input end of the first operational amplifier is a reference voltage end, the output end of the first operational amplifier is connected with the input end of the optical coupler, the output end of the optical coupler is connected with the signal input end of the voltage regulation chip, and the signal output end of the voltage regulation chip is connected with a power converter in the direct-current power supply;
the first operational amplifier is used for comparing the voltages of the voltage acquisition module and the current acquisition module with a reference voltage;
the optical coupler is used for adjusting the impedance of the output end of the optical coupler according to the comparison result;
the voltage adjusting chip is used for adjusting electric energy transmitted to a voltage output end by a power converter of the direct current power supply according to the impedance of the output end of the optical coupler, so that the output voltage of the direct current power supply is adjusted.
The first operational amplifier realizes comparison of voltage signals and has a simple structure; the optical coupler adjusts the impedance of the corresponding output pin according to the output result after comparison of the first operational amplifier, the isolation of the input end and the output end is realized through the optical coupler, and the anti-interference capability is strong; the voltage adjusting chip correspondingly adjusts the output electric energy of the power converter of the direct-current power supply according to the impedance change of the optical coupler output pin, so that the output voltage is stable.
Furthermore, the voltage acquisition module comprises a fifth resistor and a sixth resistor, the fifth resistor and the sixth resistor are connected in series and then connected with the voltage output end of the direct-current power supply, and the reverse input end of the first operational amplifier is connected between the fifth resistor and the sixth resistor.
The voltage division of the acquired output voltage is realized through the fifth resistor and the sixth resistor, and the structure is simple.
Further, the current collection module comprises a first resistor, a second resistor, a third resistor, a fourth resistor and a second operational amplifier, wherein a forward input end of the second operational amplifier is connected with a voltage output end of the direct-current power supply through the first resistor, a reverse input end of the second operational amplifier is connected with the voltage output end of the direct-current power supply through the second resistor, the third resistor is connected between the reverse input end and the output end of the second operational amplifier, and an output end of the second operational amplifier is connected with a reverse input end of the first operational amplifier through the fourth resistor;
the first resistor is used for collecting the output current of the direct current power supply;
the second resistor, the third resistor and the second operational amplifier are used for forming an amplifying circuit and converting the collected current into voltage;
the resistance value ratio of the second resistor to the third resistor is used for setting the amplification factor of converting the current into the voltage value;
the resistance value of the fourth resistor is used for adjusting the voltage division ratio of the fifth resistor and the sixth resistor.
The direct-current power supply grid-connected system comprises at least two direct-current power supplies, wherein each direct-current power supply comprises the direct-current power supply grid-connected device, and each direct-current power supply is connected with a load;
the voltage acquisition module in each direct current power supply is respectively used for acquiring the output voltage of the corresponding direct current power supply and outputting the acquired voltage to the corresponding voltage regulation module after the voltage is divided by a set proportion;
the current acquisition modules in the direct current power supplies are respectively used for acquiring output currents of the corresponding direct current power supplies, converting the acquired currents into voltages, combining the voltages with the voltages output by the corresponding voltage acquisition modules, outputting the combined voltages to the corresponding voltage regulation modules, and regulating the voltage division proportion of the corresponding voltage acquisition modules;
the voltage regulating module in each direct current power supply is used for regulating the electric energy transmitted to the voltage output end by the power converter corresponding to the direct current power supply according to the voltage of the corresponding voltage collecting module and the voltage of the corresponding current collecting module so as to regulate the output voltage of the direct current power supply and align the output voltage of each direct current power supply.
When two or more direct current power supplies are connected to the grid, the output voltage of each power supply may have deviation, the deviation causes the output current of the direct current power supplies to be different, and the direct current power supply grid-connected device carries out feedback adjustment on the output voltage of the direct current power supplies by collecting the output current and the voltage of the direct current power supplies, so that the output voltage of each direct current power supply is aligned, the temperature balance is kept, and grid-connected output is realized.
Further, the voltage regulation module in each dc power supply specifically functions as:
the first operational amplifier in each voltage regulating module compares the voltage received by the reverse input end with the reference voltage, and if the voltage received by the reverse input end is higher than the reference voltage, the voltage at the output end of the first operational amplifier is reduced; if the voltage received by the inverting input terminal is lower than the reference voltage, the voltage at the output terminal of the first operational amplifier is increased;
the optocoupler adjusts the impedance of the output end of the optocoupler according to the voltage change of the output end of the first operational amplifier, and if the voltage of the output end of the first operational amplifier is reduced, the impedance of the output end of the optocoupler is reduced; if the voltage of the output end of the first operational amplifier rises, the impedance of the output end of the optical coupler becomes large;
the voltage adjusting chip correspondingly adjusts the output voltage of the direct current power supply according to the change of the impedance of the output end of the optical coupler, and if the impedance of the output end of the optical coupler is reduced, the electric energy transmitted to the voltage output end by a power converter corresponding to the direct current power supply is reduced, so that the output voltage corresponding to the direct current power supply is reduced; if the impedance of the output end of the optical coupler is increased, the electric energy transmitted to the voltage output end by the power converter corresponding to the direct-current power supply is increased, so that the output voltage of the corresponding direct-current power supply is increased.
The voltage regulation module is simple in structure and high in anti-interference capability, and stability of the system and efficiency of voltage feedback regulation are improved.
The direct-current power supply grid-connected method is applied to the direct-current power supply grid-connected system and comprises the following steps:
step 2, the current acquisition modules in the direct current power supplies respectively acquire output currents of the corresponding direct current power supplies, convert the acquired currents into voltage values, combine the voltage values with the voltages output by the corresponding voltage acquisition modules, output the voltage values to the corresponding voltage regulation modules, and adjust the voltage division proportion of the corresponding voltage acquisition modules;
and 3, adjusting the electric energy transmitted to the voltage output end by the power converter of the corresponding direct current power supply by the voltage adjusting module in each direct current power supply according to the voltage of the corresponding voltage acquisition module and the voltage of the corresponding current acquisition module so as to adjust the output voltage of the direct current power supply, and aligning the output voltage of each direct current power supply.
Further, in step 3, the step of adjusting, by the voltage adjusting module in each dc power supply, the electric energy transmitted to the voltage output end by the power converter of the corresponding dc power supply according to the voltages of the corresponding voltage collecting module and current collecting module specifically includes:
the first operational amplifier in each voltage regulating module compares the voltage received by the reverse input end with the reference voltage, and if the voltage received by the reverse input end is higher than the reference voltage, the voltage at the output end of the first operational amplifier is reduced; if the voltage received by the reverse input end is lower than the reference voltage, the voltage of the output end of the first operational amplifier is increased;
the optocoupler adjusts the impedance of the output end of the optocoupler according to the voltage change of the output end of the first operational amplifier, and if the voltage of the output end of the first operational amplifier is reduced, the impedance of the output end of the optocoupler is reduced; if the voltage of the output end of the first operational amplifier rises, the impedance of the output end of the optical coupler becomes large;
the voltage adjusting chip correspondingly adjusts the output voltage of the direct current power supply according to the change of the impedance of the output end of the optical coupler, and if the impedance of the output end of the optical coupler is reduced, the electric energy transmitted to the voltage output end by a power converter corresponding to the direct current power supply is reduced, so that the output voltage corresponding to the direct current power supply is reduced; if the impedance of the output end of the optical coupler is increased, the electric energy transmitted to the voltage output end by the power converter corresponding to the direct-current power supply is increased.
The beneficial effects of the invention are as follows:
the invention simplifies the grid-connected mode through the direct current power supply grid-connected device, does not need the design of a current-sharing bus, and reduces the wiring of a direct current power supply system.
According to the invention, the output voltage and current of the direct current power supply are collected and fed back to the voltage regulating module, and the voltage regulating module regulates the output voltage according to the feedback signal, so that the power supplies with different types and powers can be conveniently connected to the grid, and the grid connection compatibility is improved.
Drawings
FIG. 1 is a schematic diagram of the voltage and current characteristics of a conventional power supply output in a prior art scheme;
FIG. 2 is a schematic diagram of a grid-connected DC power supply in a conventional scheme;
FIG. 3 is a schematic diagram illustrating voltage and current characteristics of the DC power output according to the present invention;
fig. 4 is a block diagram of a dc power supply according to an embodiment of the present invention;
fig. 5 is a circuit diagram of a dc power supply according to an embodiment of the invention;
fig. 6 is a block diagram of a dc power supply grid-connected system according to an embodiment of the present invention.
In the drawing, U2A is a first operational amplifier, U2B is a second operational amplifier, R1 is a first resistor, R2 is a second resistor, R3 is a third resistor, R4 is a fourth resistor, R5 is a fifth resistor, R6 is a sixth resistor, R7 is a seventh resistor, R8 is an eighth resistor, R9 is a ninth resistor, R10 is a tenth resistor, R11 is an eleventh resistor, and R12 is a twelfth resistor.
Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention. It is to be understood that the embodiments described are only a few embodiments of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
Fig. 4 is a block diagram of a dc power supply according to an embodiment of the present invention, where the dc power supply includes a voltage acquisition module, a current acquisition module, a voltage regulation module, and a power converter;
the voltage acquisition module is used for acquiring the output voltage of the direct-current power supply, and outputting the acquired voltage to the voltage regulation module after the acquired voltage is divided by a set proportion;
the current acquisition module is used for acquiring the output current of the direct current power supply, converting the acquired current into voltage, combining the voltage with the voltage output by the voltage acquisition module, outputting the voltage to the voltage regulation module and regulating the voltage division proportion of the voltage acquisition module;
and the voltage regulating module is used for regulating the electric energy transmitted to the voltage output end by the power converter according to the voltages of the voltage acquisition module and the current acquisition module so as to regulate the output voltage of the direct current power supply.
In this embodiment, the power converter is usually implemented by using a transformer.
Fig. 5 is a circuit diagram of a dc power supply according to an embodiment of the present invention, as shown in the figure,
the voltage acquisition module comprises a fifth resistor R5 and a sixth resistor R6, the fifth resistor R5 and the sixth resistor R6 are connected in series and then connected with a voltage output end outputVCC of the direct-current power supply, and the reverse input end 2 of the first operational amplifier U2A is connected between the fifth resistor R5 and the sixth resistor R6.
The current collection module comprises a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4 and a second operational amplifier U2B, wherein a forward input end 5 of the second operational amplifier U2B is connected with a voltage output end outputGND of the direct-current power supply through the first resistor R1, a reverse input end 6 of the second operational amplifier U2B is connected with the voltage output end outputGND of the direct-current power supply through the second resistor R2, the third resistor R3 is connected between the reverse input end 6 and an output end 7 of the second operational amplifier U2B, and the output end 7 of the second operational amplifier U2B is connected with the reverse input end 2 of the first operational amplifier U2A through the fourth resistor R4;
acquiring the output current of a direct current power supply through a first resistor R1; the second resistor R2, the third resistor R3 and the second operational amplifier U2B form an amplifying circuit, and the acquired current is converted into voltage; the amplification factor of converting the current into the voltage value is set according to the resistance ratio of the second resistor R2 to the third resistor R3; the voltage division ratio of the fifth resistor R5 and the sixth resistor R6 is adjusted through the resistance of the fourth resistor R4.
When the output current is 0, that is, no current flows through the first resistor R1, and the voltage of the output terminal 7 pin of the second operational amplifier U2B is the lowest, the output voltage of the power supply output voltage outputVCC is the highest. When the output current is maximum (full load), i.e. the current flowing through the resistor of the first resistor R1 is maximum, and the voltage of the pin 7 at the output end of the second operational amplifier U2B is highest, the output voltage of the power output vcc is lowest. In this way, the power output voltage will reach the voltage and current characteristics as shown in fig. 3, i.e. the power output voltage of the present invention varies with the output load current, the output voltage is U0 when the output current is zero, and the output voltage is U0 'when the output current is the rated current I0, i.e. U0' after Δ U is decreased based on the output U0.
The voltage regulation module comprises a first operational amplifier U2A, an optical coupler U3 and a voltage regulation chip U1, wherein a positive input end 2 of the first operational amplifier U2A is a reference voltage Vref, and the reference voltage Vref is generated by a reference voltage source TL 431; the output end 1 of the first operational amplifier U2A is connected with the input end 2 of the optocoupler U3; the first operational amplifier U2A compares the voltage received by the inverting input end 2 with the reference voltage Vref, and if the voltage received by the inverting input end 2 is higher than the reference voltage Vref, the voltage at the output end of the first operational amplifier U2A is reduced; if the voltage received by the inverting input terminal 2 is lower than the reference voltage Vref, the voltage at the output terminal of the first operational amplifier U2A increases.
An input end 1 of the optocoupler U3 is connected with a voltage output end outputVCC through a resistor R8, an output end 4 of the optocoupler U3 is connected with a signal input end 3 of the voltage adjusting chip U1 through a resistor R9, and an output end 3 of the optocoupler U3 is grounded; the optocoupler U3 adjusts the impedance of the output ends 3 and 4 of the optocoupler according to the voltage change of the output end 1 of the first operational amplifier U2A, if the voltage of the output end 1 of the first operational amplifier U2A is reduced, the current of the input ends 1 and 2 of the optocoupler U3 is increased, and the impedance of the output ends 3 and 4 of the optocoupler U3 is reduced; if the voltage of the output end 1 of the first operational amplifier U2A is increased, the impedance of the output ends 3 and 4 of the optocoupler U3 is increased;
a power supply end 1 of the voltage adjusting chip U1 is connected with a power supply input end inputVCC through a resistor R10, the power supply input end inputVCC is connected with a cathode of a diode D1 through a resistor R11, an anode of the diode D1 is connected with a signal output end 4 of the voltage adjusting chip U1, the signal output end 4 of the voltage adjusting chip U1 is also connected with a main coil of the transformer T1, and a grounding end 2 of the voltage adjusting chip U1 is grounded; the power input end inputVCC is also connected with the primary coil of the transformer T1, and the secondary coil is connected with the voltage output end outputVCC of the direct-current power supply;
the voltage adjusting chip U1 correspondingly adjusts the electric energy output of the transformer T1 according to the impedance change of the output ends 3 and 4 of the optocoupler U3, and if the impedances of the output ends 3 and 4 of the optocoupler become smaller, the electric energy output of the transformer T1 is correspondingly reduced; if the impedances of the output ends 3 and 4 of the optocoupler U3 are increased, the electric energy output of the transformer T1 is correspondingly increased.
The voltage regulation chip U1 controls the signal output of the power supply chip by PWM (i.e., pulse width modulation). During specific adjustment, if the impedances of the output ends 3 and 4 of the optocoupler U3 are reduced, the waveform width output by the output end 4 of the U1 is adjusted to be narrow (which is equivalent to a switching tube of a switching power supply, and has short turn-on time and long turn-off time), so that the electric energy transmitted to the voltage output end output VCC by the transformer T1 is reduced, and the output voltage of the power supply is reduced;
if the impedance of the output end 3 and the impedance of the output end 4 of the optocoupler U3 are increased, the waveform width output by the output end 4 of the U1 is widened (equivalent to a switching tube of a switching power supply, the switching-on time is long, and the switching-off time is short), so that the electric energy transmitted to the voltage output end outputVCC by the transformer T1 is increased, and the output voltage of the power supply is increased.
Fig. 6 is a structural block diagram of a dc power supply grid-connected system according to an embodiment of the present invention, where as shown in the figure, the grid-connected system includes at least two dc power supplies, each dc power supply includes a dc power supply grid-connected device according to the present invention, and each dc power supply is connected to a load;
the voltage acquisition module in each direct current power supply is respectively used for acquiring the output voltage of the corresponding direct current power supply and outputting the acquired voltage to the corresponding voltage regulation module after the voltage is divided by a set proportion;
the current acquisition modules in the direct current power supplies are respectively used for acquiring output currents of the corresponding direct current power supplies, converting the acquired currents into voltages, combining the voltages with the voltages output by the corresponding voltage acquisition modules, outputting the combined voltages to the corresponding voltage regulation modules, and regulating the voltage division proportion of the corresponding voltage acquisition modules;
and the voltage regulating module in each direct current power supply is used for regulating the electric energy transmitted to the voltage output end by the transformer of the corresponding direct current power supply according to the voltage of the corresponding voltage collecting module and the voltage of the corresponding current collecting module so as to regulate the output voltage of the direct current power supply, so that the output voltage of each direct current power supply is aligned and kept balanced.
The voltage regulation module in each direct current power supply has the following specific functions:
the first operational amplifier in each voltage regulating module compares the voltage received by the reverse input end with the reference voltage, and if the voltage received by the reverse input end is higher than the reference voltage, the voltage at the output end of the first operational amplifier is reduced; if the voltage received by the inverting input terminal is lower than the reference voltage, the voltage at the output terminal of the first operational amplifier is increased;
the optocoupler adjusts the impedance of the output end of the optocoupler according to the voltage change of the output end of the first operational amplifier, and if the voltage of the output end of the first operational amplifier is reduced, the impedance of the output end of the optocoupler is reduced; if the voltage of the output end of the first operational amplifier rises, the impedance of the output end of the optical coupler becomes large;
the voltage adjusting chip correspondingly adjusts the output voltage of the direct current power supply according to the change of the impedance of the output end of the optical coupler, and if the impedance of the output end of the optical coupler is reduced, the electric energy transmitted to the voltage output end by the corresponding direct current power supply transformer is reduced, so that the output voltage of the corresponding direct current power supply is reduced; if the impedance of the output end of the optical coupler is increased, the electric energy transmitted to the voltage output end by the corresponding direct-current power supply transformer is increased, and therefore the output voltage of the corresponding direct-current power supply is increased.
According to the direct-current power supply grid-connected system, the invention also provides a direct-current power supply grid-connected method, which comprises the following steps:
step 2, the current acquisition modules in the direct current power supplies respectively acquire output currents of the corresponding direct current power supplies, convert the acquired currents into voltage values, combine the voltage values with the voltages output by the corresponding voltage acquisition modules and then output the voltage values to the corresponding voltage regulation modules, and adjust the voltage division ratio of the corresponding voltage acquisition modules;
and 3, adjusting the electric energy transmitted to the voltage output end by the transformer of the corresponding direct current power supply by the voltage adjusting module in each direct current power supply according to the voltage of the corresponding voltage acquisition module and the voltage of the corresponding current acquisition module so as to adjust the output voltage of the direct current power supply, and aligning the output voltage of each direct current power supply.
In step 3, the voltage regulation module in each dc power supply adjusts the electric energy transmitted to the voltage output end by the transformer corresponding to the dc power supply according to the voltage of the corresponding voltage acquisition module and the voltage of the corresponding current acquisition module, and specifically includes:
the first operational amplifier in each voltage regulating module compares the voltage received by the reverse input end with the reference voltage, and if the voltage received by the reverse input end is higher than the reference voltage, the voltage at the output end of the first operational amplifier is reduced; if the voltage received by the inverting input terminal is lower than the reference voltage, the voltage at the output terminal of the first operational amplifier is increased;
the optocoupler adjusts the impedance of the output end of the optocoupler according to the voltage change of the output end of the first operational amplifier, and if the voltage of the output end of the first operational amplifier is reduced, the impedance of the output end of the optocoupler is reduced; if the voltage of the output end of the first operational amplifier rises, the impedance of the output end of the optical coupler becomes large;
the voltage adjusting chip correspondingly adjusts the output voltage of the direct current power supply according to the change of the impedance of the output end of the optical coupler, and if the impedance of the output end of the optical coupler is reduced, the electric energy transmitted to the voltage output end by the corresponding direct current power supply transformer is reduced, so that the output voltage of the corresponding direct current power supply is reduced; and if the impedance of the output end of the optical coupler is increased, the electric energy transmitted to the voltage output end by the corresponding direct-current power supply transformer is increased.
The principle of the direct-current power supply grid connection of the invention is as follows: when two or more direct current power supplies are connected to the grid, the output voltage of each direct current power supply may have deviation, and the deviation causes that the output current may have difference after the direct current power supplies are connected to the load in a grid-connected mode. Therefore, the direct current power supply grid-connected device carries out feedback real-time regulation on the output voltage of the direct current power supply by collecting the output current and the output voltage of the direct current power supply, so that the output voltages of the direct current power supplies are aligned, the output balance is kept, and stable grid-connected output is realized.
In conclusion, the design of the current-sharing bus is not adopted, the grid-connected connection mode is simplified, the wiring of a direct-current power supply system is reduced, the grid-connected compatibility is greatly improved, and the grid connection of power supplies with different types and powers can be easier.
Claims (8)
1. The direct current power supply grid-connected device is characterized by comprising a voltage acquisition module, a current acquisition module and a voltage regulation module;
the voltage acquisition module is used for acquiring the output voltage of the direct-current power supply and outputting the acquired voltage to the voltage regulation module after the voltage is divided by a set proportion;
the current acquisition module is used for acquiring the output current of the direct current power supply, converting the acquired current into voltage, combining the voltage with the voltage output by the voltage acquisition module, outputting the voltage to the voltage regulation module and regulating the voltage division proportion of the voltage acquisition module;
and the voltage regulating module is used for regulating the electric energy transmitted to the voltage output end by the power converter of the direct current power supply according to the voltages of the voltage collecting module and the current collecting module so as to regulate the output voltage of the direct current power supply.
2. The direct-current power supply grid-connected device according to claim 1, wherein the voltage regulation module comprises a first operational amplifier, an optical coupler and a voltage regulation chip, a reverse input end of the first operational amplifier is respectively connected with the voltage collection module and the current collection module, a forward input end of the first operational amplifier is a reference voltage end, an output end of the first operational amplifier is connected with an input end of the optical coupler, an output end of the optical coupler is connected with a signal input end of the voltage regulation chip, and a signal output end of the voltage regulation chip is connected with a power converter in a direct-current power supply;
the first operational amplifier is used for comparing the voltages of the voltage acquisition module and the current acquisition module with a reference voltage;
the optical coupler is used for adjusting the impedance of the output end of the optical coupler according to the comparison result;
the voltage adjusting chip is used for adjusting electric energy transmitted to a voltage output end by a power converter of the direct current power supply according to the impedance of the output end of the optical coupler, so that the output voltage of the direct current power supply is adjusted.
3. The direct-current power supply grid-connected device according to claim 2, wherein the voltage acquisition module comprises a fifth resistor and a sixth resistor, the fifth resistor and the sixth resistor are connected in series and then connected with a voltage output end of the direct-current power supply, and an inverting input end of the first operational amplifier is connected between the fifth resistor and the sixth resistor.
4. The DC power supply grid-connected device according to claim 3, wherein the current collection module comprises a first resistor, a second resistor, a third resistor, a fourth resistor and a second operational amplifier, a forward input end of the second operational amplifier is connected with a voltage output end of the DC power supply through the first resistor, an inverting input end of the second operational amplifier is connected with the voltage output end of the DC power supply through the second resistor, the third resistor is connected between the inverting input end and the output end of the second operational amplifier, and the output end of the second operational amplifier is connected with the inverting input end of the first operational amplifier through the fourth resistor;
the first resistor is used for collecting the output current of the direct current power supply;
the second resistor, the third resistor and the second operational amplifier are used for forming an amplifying circuit and converting the collected current into voltage;
the resistance value ratio of the second resistor to the third resistor is used for setting the amplification factor of converting the current into the voltage value;
the resistance value of the fourth resistor is used for adjusting the voltage division ratio of the fifth resistor and the sixth resistor.
5. The direct-current power supply grid-connected system is characterized by comprising at least two direct-current power supplies, wherein the direct-current power supplies comprise the direct-current power supply grid-connected device as claimed in any one of claims 1 to 4, and each direct-current power supply is connected with a load;
the voltage acquisition modules in the direct current power supplies are respectively used for acquiring output voltages of the corresponding direct current power supplies and outputting the acquired voltages to the corresponding voltage regulation modules after the acquired voltages are subjected to voltage division according to a set proportion;
the current acquisition modules in the direct current power supplies are respectively used for acquiring output currents of the corresponding direct current power supplies, converting the acquired currents into voltages, combining the voltages with the voltages output by the corresponding voltage acquisition modules, outputting the combined voltages to the corresponding voltage regulation modules, and regulating the voltage division proportion of the corresponding voltage acquisition modules;
the voltage regulating module in each direct current power supply is used for regulating the electric energy transmitted to the voltage output end by the power converter corresponding to the direct current power supply according to the voltage of the corresponding voltage collecting module and the voltage of the corresponding current collecting module so as to regulate the output voltage of the direct current power supply and align the output voltage of each direct current power supply.
6. The DC power supply grid-connected system according to claim 5, wherein the voltage regulation module in each DC power supply specifically functions as:
the first operational amplifier in each voltage regulating module compares the voltage received by the reverse input end with the reference voltage, and if the voltage received by the reverse input end is higher than the reference voltage, the voltage at the output end of the first operational amplifier is reduced; if the voltage received by the inverting input terminal is lower than the reference voltage, the voltage at the output terminal of the first operational amplifier is increased;
the optocoupler adjusts the impedance of the output end of the optocoupler according to the voltage change of the output end of the first operational amplifier, and if the voltage of the output end of the first operational amplifier is reduced, the impedance of the output end of the optocoupler is reduced; if the voltage of the output end of the first operational amplifier rises, the impedance of the output end of the optical coupler becomes large;
the voltage adjusting chip correspondingly adjusts the output voltage of the direct current power supply according to the change of the impedance of the output end of the optical coupler, and if the impedance of the output end of the optical coupler is reduced, the electric energy transmitted to the voltage output end by a power converter corresponding to the direct current power supply is reduced, so that the output voltage corresponding to the direct current power supply is reduced; if the impedance of the output end of the optical coupler is increased, the electric energy transmitted to the voltage output end by the power converter corresponding to the direct-current power supply is increased, so that the output voltage of the corresponding direct-current power supply is increased.
7. The direct current power supply grid-connected method is applied to the direct current power supply grid-connected system according to claim 5 or 6, and is characterized by comprising the following steps:
step 1, respectively collecting output voltages of corresponding direct current power supplies by a voltage collection module in each direct current power supply, and outputting the collected voltages to corresponding voltage regulation modules after voltage division by a set proportion;
step 2, the current acquisition modules in the direct current power supplies respectively acquire output currents of the corresponding direct current power supplies, convert the acquired currents into voltage values, combine the voltage values with the voltages output by the corresponding voltage acquisition modules, output the voltage values to the corresponding voltage regulation modules, and adjust the voltage division proportion of the corresponding voltage acquisition modules;
and 3, adjusting the electric energy transmitted to the voltage output end by the power converter of the corresponding direct current power supply by the voltage adjusting module in each direct current power supply according to the voltage of the corresponding voltage acquisition module and the voltage of the corresponding current acquisition module so as to adjust the output voltage of the direct current power supplies and align the output voltage of each direct current power supply.
8. The dc power supply grid connection method according to claim 7, wherein in step 3, the voltage adjustment module in each dc power supply adjusts electric energy transmitted to the voltage output terminal by the power converter of the corresponding dc power supply according to the voltage of the corresponding voltage acquisition module and the voltage of the corresponding current acquisition module, and specifically comprises:
the first operational amplifier in each voltage regulating module compares the voltage received by the inverting input end with the reference voltage, and if the voltage received by the inverting input end is higher than the reference voltage, the voltage at the output end of the first operational amplifier is reduced; if the voltage received by the reverse input end is lower than the reference voltage, the voltage of the output end of the first operational amplifier is increased;
the optocoupler adjusts the impedance of the output end of the optocoupler according to the voltage change of the output end of the first operational amplifier, and if the voltage of the output end of the first operational amplifier is reduced, the impedance of the output end of the optocoupler is reduced; if the voltage of the output end of the first operational amplifier rises, the impedance of the output end of the optical coupler becomes large;
the voltage adjusting chip correspondingly adjusts the output voltage of the direct current power supply according to the change of the impedance of the output end of the optical coupler, and if the impedance of the output end of the optical coupler is reduced, the electric energy transmitted to the voltage output end by a power converter corresponding to the direct current power supply is reduced, so that the output voltage corresponding to the direct current power supply is reduced; if the impedance of the output end of the optical coupler is increased, the electric energy transmitted to the voltage output end by the power converter corresponding to the direct-current power supply is increased.
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN117507914A (en) * | 2024-01-05 | 2024-02-06 | 深圳市丁旺科技有限公司 | Charging pile charging module and current equalizing method |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN117507914A (en) * | 2024-01-05 | 2024-02-06 | 深圳市丁旺科技有限公司 | Charging pile charging module and current equalizing method |
| CN117507914B (en) * | 2024-01-05 | 2024-05-14 | 深圳市丁旺科技有限公司 | Charging pile charging module and current equalizing method |
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