CN115603390A - AC/DC compatible double-circuit power supply circuit and method - Google Patents

Abstract

The invention discloses a power supply circuit and a method compatible with an alternating current-direct current double-circuit power supply, the circuit comprises an alternating current power supply port, a direct current power supply port, a fan port, an AC-DC conversion unit and a main control unit, wherein the alternating current power supply port is used for accessing an alternating current power supply, the direct current power supply port is used for accessing a direct current power supply, the alternating current power supply is used for providing alternating current, the direct current power supply is used for providing first direct current, the fan port is used for electrically connecting a fan, the main control unit is provided with an alternating current input end, a direct current input end and a load end, the main control unit can access the direct current power supply through the direct current input end for supplying power, the load end is used for electrically connecting a compressor, the alternating current input end is respectively electrically connected with the input end of the AC-DC conversion unit and the alternating current power supply port, the AC-DC conversion unit is used for converting the alternating current into second direct current with the same voltage as the first direct current, and the second direct current are connected in parallel and then used for supplying power to the fan; the invention can realize the compatibility of the air conditioning unit with AC/DC double-circuit power supply, and has high safety and controllable cost.

Description

AC/DC compatible double-circuit power supply circuit and method

Technical Field

The invention relates to the technical field of power supply, in particular to a power supply circuit and a power supply method compatible with an alternating current-direct current double-circuit power supply.

Background

At present, for a single-phase AC220V variable frequency compressor load and a DC48V fan load, double-circuit power supply of a first power supply AC220V and a second power supply DC48V needs to be realized, and the requirements are that an inner fan and an outer fan run to perform heat pipe heat dissipation when a mains supply (AC 220V) is powered off or an air conditioning unit fails, and the conventional scheme in the industry is as follows:

scheme 1: an inverter is added at the rear end of a second power supply (DC 48V) to convert the DC48V into AC220V, part of the power supply of the fan directly gets electricity from the DC48V power supply, a compressor driving plate and a main control plate part get electricity after the first power supply of the AC220V is connected with the output side of the inverter in parallel, the main control plate supplies electricity by AC220V, a control port (0-10V control) of a related fan is integrated on the main control plate, the compressor control adopts 485 communication control, namely the main control plate and the compressor driving plate carry out startup and shutdown by 485 communication, and other loads (electromagnetic valves and the like) are all AC220V and can be directly output from a D0 port of the main control plate;

scheme 2: a single-phase rectifier transformer (rectifier) is added at the rear end of a first power supply (AC 220V), the AC220V power supply is rectified into a DC48V power supply, a compressor driving board gets power from the front of the first power supply (AC 220V) single-phase rectifier transformer, a fan part (DC 48V) gets power from the output side of the single-phase rectifier transformer after being connected with a second power supply (DC 48V) in parallel, the main control board part supplies power by adopting the DC48V, a control port (0-10V control) of a related fan is integrated on the main control board, the compressor control is controlled by 485 communication, namely the main control board and the compressor driving board carry out startup and shutdown by 485 communication, other loads (electromagnetic valves and the like) adopt the DC48V or the DC24V, and the control method is safer compared with a first scheme (adopting an AC220V electromagnetic valve).

However, the inverter is required to be used in the scheme 1, which is high in cost and large in occupied size, while the single-phase rectifier transformer (rectifier) is required to be used in the scheme 2, which is high in cost and large in occupied size, and meanwhile, the control panel is powered by the DC48V, so that the number of controllers which are separately powered by the DC48V in the market is small, and the production cost is undoubtedly increased due to a non-standard design. In addition, for the scheme 1 and the scheme 2, if two power supplies (AC 220V and DC 48V) of a customer are connected reversely, the fans of the unit, even the main control board, are damaged.

Disclosure of Invention

The invention aims to provide a compatible AC/DC double-circuit power supply circuit and a method, which can realize the compatibility of AC/DC double-circuit power supply for an air conditioning unit, and have high safety and controllable cost.

In order to achieve the above purpose, the present invention discloses a power supply circuit compatible with an AC-DC dual-channel power supply, which includes an AC power supply port, a DC power supply port, a fan port, an AC-DC conversion unit and a main control unit, wherein the AC power supply port is configured to access an AC power supply, the DC power supply port is configured to access a DC power supply, the AC power supply is configured to provide an AC power, the DC power supply is configured to provide a first DC power, the fan port is configured to electrically connect to a fan, the main control unit is provided with an AC input terminal, a DC input terminal and a load terminal, the main control unit can access the DC power supply through the DC input terminal to supply power, the load terminal is configured to electrically connect to a compressor, the AC input terminal is respectively electrically connected to the AC-DC conversion unit input terminal and the AC power supply port, the AC-DC conversion unit is configured to convert an AC power to a second DC power having a voltage identical to that of the first DC power, and the first DC power and the second DC power are connected in parallel to supply power to the fan.

Preferably, the air circuit breaker further comprises an ac air switch and a dc air switch, the ac air switch is connected in series to the loop where the ac power supply port is located, and the dc air switch is connected in series to the loop where the dc power supply port is located.

Preferably, the compatible AC-DC dual-channel power supply circuit further includes a rectification module, an output terminal of the AC-DC conversion unit is electrically connected to a first input terminal of the rectification module, the DC power supply port is electrically connected to a second input terminal of the rectification module, an output terminal of the rectification module is electrically connected to the fan port, and the rectification module is configured to connect the first DC power and the second DC power in parallel and then supply power to the fan.

Specifically, the rectifying module includes a first diode, a second diode, a third diode and a fourth diode, a cathode of the first diode is electrically connected to an anode of the second diode, a cathode of the third diode is electrically connected to an anode of the fourth diode, an anode of the first diode is connected to an anode of the third diode, a cathode of the second diode is electrically connected to a cathode of the fourth diode, and then the cathode of the second diode is electrically connected to the fan port, the DC power supply port is electrically connected between the cathode of the first diode and the anode of the second diode, and an output terminal of the AC-DC conversion unit is electrically connected between the cathode of the third diode and the anode of the fourth diode.

Preferably, the compatible ac/dc dual-channel power supply circuit further includes a voltage monitoring unit and an ac contactor, the voltage monitoring unit and the ac contactor are connected in series and then connected in series to a loop where the dc power supply port is located, a control coil of the ac contactor is controlled by the first dc power, and when the dc power supply port is connected to the dc power supply, a normally closed contact of the voltage monitoring unit is kept normally closed, so that the control coil of the ac contactor is powered on, and the loop where the dc power supply port is located is turned on; when the direct current power supply port is switched in the alternating current power supply by mistake, the normally closed contact of the voltage monitoring unit is disconnected, so that the control coil of the alternating current contactor is not electrified, and the loop where the direct current power supply port is located is disconnected.

Preferably, the main control unit is further configured to sample voltage of the fan and perform under-voltage and over-voltage protection on the fan.

The power supply circuit comprises a master control unit, a fan control end, a first starting resistor, a second starting resistor and a relay, wherein the master control unit is further provided with the fan control end used for being electrically connected with the PWM end and comprises a PWM chip, the first starting resistor, the second starting resistor and the relay; when the input voltage is low voltage, the control coil of the relay is controlled to be electrified so as to close the relay, and the starting circuit is equivalent to a circuit only provided with a first starting resistor.

Preferably, the compatible ac/dc dual-path power supply circuit further includes a driving unit for driving the compressor, an input end of the driving unit is connected to the load end, and an output end of the driving unit is electrically connected to the compressor; the main control unit is also provided with a direct current input end, and the main control unit can be connected with a direct current power supply through the direct current input end to supply power.

Preferably, the voltage of the alternating current is 220V, and the voltage of the first direct current and the voltage of the second direct current are both 48V.

Correspondingly, the invention also discloses a compatible alternating current-direct current double-circuit power supply method, which is applied to the compatible alternating current-direct current double-circuit power supply circuit, and the compatible alternating current-direct current double-circuit power supply circuit control method comprises the following steps:

when the alternating current power supply supplies power normally, the control unit is powered by alternating current provided by the alternating current power supply, and the fan is powered after the alternating current is converted into second direct current by the AC-DC conversion unit;

when the alternating current power supply is abnormal, the first direct current provided by the direct current power supply supplies power to the fan.

Compared with the prior art, the main control unit can be connected with a direct-current power supply through the direct-current input end for supplying power, the alternating-current input end is respectively and electrically connected with the input end of the AC-DC conversion unit and the alternating-current power supply port, the AC-DC conversion unit is used for converting alternating current into second direct current with the same voltage as that of the first direct current, and the first direct current and the second direct current are connected in parallel and then supply power to the fan; on the other hand, after the alternating current is converted into the second direct current with the same voltage as the first direct current through the AC-DC conversion unit, the first direct current and the second direct current are connected in parallel and then supply power to the fan, so that the fan can be kept in a power supply state, the fan is prevented from being stopped due to failure of the alternating current power supply or the direct current power supply, and safety accidents caused by low heat exchange efficiency due to untimely heat dissipation of the heat pipe caused by the stop of the fan are effectively prevented.

Drawings

FIG. 1 is a circuit diagram of a compatible AC/DC dual power supply circuit of the present invention;

FIG. 2 is a circuit schematic of a rectifier module of the present invention;

FIG. 3 is a circuit schematic of the start-up unit of the present invention;

fig. 4 is a flow chart of the method for supplying power compatible with the ac/dc two-way power supply of the invention.

Detailed Description

In order to explain technical contents, structural features, and objects and effects of the present invention in detail, the following detailed description is given with reference to the accompanying drawings in conjunction with the embodiments.

Referring to fig. 1-3, the ac/dc dual-path power supply circuit of the present embodiment is suitable for supplying power to a compressor 90 of an air conditioner. This compatible alternating current-direct current dual-circuit power supply circuit includes alternating current power supply port 10, direct current power supply port 20, fan port 30, AC-DC conversion unit 40 and main control unit 50, alternating current power supply port 10 is used for inserting alternating current power supply 60, direct current power supply port 20 is used for inserting direct current power supply 70, alternating current power supply 60 is used for providing the alternating current, direct current power supply 70 is used for providing first direct current, fan port 30 is used for electric connection fan 80.

It can be understood that the ac power supply 60 is a commercial power supply which provides 220V ac power, the dc power supply 70 is a lithium battery, a lead-acid battery or an uninterruptible power supply, the dc power supply 70 provides 48V dc power, the operating voltage of the fan 80 is 48V, and the adjustable control voltage range of the fan 80 is 0V to 10V. Of course, in other embodiments, the commercial power voltage, the voltage of the dc power supply 70, the operating voltage of the fan 80, and the adjustable control voltage range of the fan 80 may all be adjusted according to actual requirements, and are not limited herein. The main control unit 50 of this embodiment is a main control chip having a plurality of types of interfaces, and programs are written into the main control chip to implement different functions of different interfaces.

The main control unit 50 is provided with an alternating current input end 51, a direct current input end 52 and a load end 53, the main control unit 50 can be connected to a direct current power supply 70 through the direct current input end 52 for supplying power, the load end 53 is used for electrically connecting a compressor 90, and the alternating current input end 51 is electrically connected with the input end of the AC-DC conversion unit 40 and the alternating current power supply port 10 respectively.

It can be understood that, because the main control unit 50 is powered by ac power through the ac input terminal 51, and the main control unit 50 reserves a backup power supply mode for supplying power through the dc input terminal 52, when the ac power supply 60 fails, dc power can be accessed through the dc input terminal 52 for emergency power supply, so as to ensure that the main control unit 50 can perform basic operations such as speed regulation control of the fan 80.

The AC-DC conversion unit 40 is configured to convert an alternating current to a second direct current having a voltage identical to that of the first direct current, and the first direct current and the second direct current are connected in parallel and then supply power to the fan 80, so that the fan 80 can be supplied with power by the direct current power supply 70 after the alternating current power supply 60 fails, the fan 80 can maintain normal blowing and heat dissipation of the heat pipe, and safety accidents caused by low heat exchange efficiency due to untimely heat dissipation of the heat pipe caused by shutdown of the fan 80 are effectively prevented.

It should be noted that the ac/dc dual-path power supply circuit of the present invention can control a plurality of fans 80 to work, wherein one of the fans 80 is an indoor fan 80, and the other fan 80 is an outdoor fan 80. For convenience of explanation, the present embodiment only describes the operation of the single fan 80.

Preferably, the compatible ac/dc two-way power supply circuit further includes an ac air switch 100 and a dc air switch 110, the ac air switch 100 is connected in series to the loop where the ac power supply port 10 is located, and the dc air switch 110 is connected in series to the loop where the dc power supply port 20 is located, so as to avoid equipment damage caused by excessive supply current of any one of the two circuits.

Preferably, the compatible AC/DC dual-channel power supply circuit further includes a rectifying module 120 as shown in fig. 2, the output terminal of the AC-DC conversion unit 40 is electrically connected to the first input terminal of the rectifying module 120, the DC power supply port 20 is electrically connected to the second input terminal of the rectifying module 120, the output terminal of the rectifying module 120 is electrically connected to the fan port 30, and the rectifying module 120 is configured to connect the first DC power and the second DC power in parallel and then supply power to the fan 80, and limit any one of the first DC power and the second DC power to supply power to the fan 80.

Specifically, the rectification module 120 includes a first diode D1, a second diode D2, a third diode D3, and a fourth diode D4, a cathode of the first diode D1 is electrically connected to an anode of the second diode D2, a cathode of the third diode D3 is electrically connected to an anode of the fourth diode D4, an anode of the first diode D1 is connected to an anode of the third diode D3, a cathode of the second diode D2 is electrically connected to an anode of the fourth diode D4, and then is electrically connected to the fan port 30, the DC power supply port 20 is electrically connected between the cathode of the first diode D1 and the anode of the second diode D2, and an output end of the AC-DC conversion unit 40 is electrically connected between the cathode of the third diode D3 and the anode of the fourth diode D4.

It can be understood that the rectification and reverse connection prevention can be realized by adopting the diode combination, the traditional single-phase rectifier transformer is not required to be adopted for rectification, and the circuit rectification cost and the equipment volume are effectively reduced. In addition, when the alternating current power supply 60 and the direct current power supply 70 both supply power normally, the diode combination limits only one current to be output through the diode combination, and effectively avoids mutual interference of two currents due to simultaneous output and component damage caused by mutual interference of the currents.

Preferably, the compatible ac/dc two-way power supply circuit further includes a voltage monitoring unit 130 and an ac contactor 140, the voltage monitoring unit 130 and the ac contactor 140 are connected in series and then connected in series to the loop where the dc power supply port 20 is located, the control coil of the ac contactor 140 is controlled by the first dc power, and when the dc power supply port 20 is connected to the dc power supply 70, the normally open contact of the voltage monitoring unit 130 is turned on to a closed state after being actuated, so that the control coil of the ac contactor 140 is energized to conduct the loop where the dc power supply port 20 is located; when the dc power supply port 20 is erroneously connected to the ac power supply 60, the normally open contact of the voltage monitoring unit 130 does not operate to keep the original state of disconnection, so that the control coil of the ac contactor 140 is not powered, and the loop where the dc power supply port 20 is located is disconnected, thereby ensuring that the fan 80 cannot obtain power supply when the dc power supply port 20 is erroneously connected to the ac power supply 60, and ensuring that the fan 80 is not damaged due to the access of an excessively high voltage.

Preferably, the main control unit 50 is further configured to sample a voltage of the fan 80, and perform under-voltage and over-voltage protection on the fan 80. Specifically, the compatible alternating current-direct current dual-path power supply circuit further includes a starting unit 150 as shown in fig. 3, the fan 80 includes a PWM end, the main control unit 50 is further provided with a fan control end 54 for electrically connecting the PWM end, the main control unit 50 includes a PWM chip 151, a first starting resistor R1, a second starting resistor R2 and a relay 152, the first starting resistor R1 and the second starting resistor R2 are sequentially connected in series to form a starting circuit, the resistance value of the first starting resistor R1 is smaller than that of the second starting resistor R2, the second starting resistor R2 is electrically connected to the input end of the PWM chip 151, the output end of the PWM chip 151 is electrically connected to the fan control end 54, the relay 152 and the second starting resistor R2 are arranged in parallel, the relay 152 is a normally open contact relay, a control coil of the relay 152 is electrically connected to the main control unit 50, and the main control unit 50 controls the on/off of the relay 152 by controlling whether the control coil of the relay 152 is energized.

Specifically, when the input voltage is a high voltage, the control coil of the relay 152 is controlled not to be powered to keep the relay 152 disconnected, the starting circuit is formed by connecting the first starting resistor R1 and the second starting resistor R2 in series, so that the high voltage corresponds to a high resistance value, and the first starting resistor R1 and the second starting resistor R2 are connected in series and then divided to ensure that the power of any starting resistor is not too large, thereby avoiding abnormal temperature rise caused by too large power of any starting resistor.

When the input voltage is low voltage, the control coil of the relay 152 is controlled to be electrified to close the relay 152, the starting circuit is equivalent to a circuit only provided with the first starting resistor R1, so that the starting circuit only plays a role in the first starting resistor R1 actually, the low voltage corresponds to a low resistance value, and the PWM chip 151 is started with the minimum starting current.

Preferably, the compatible ac/dc dual-channel power supply circuit further includes a driving unit 160 for driving the compressor 90, an input end of the driving unit 160 is connected to the load end 53, and an output end is electrically connected to the compressor 90.

Referring to fig. 1-4, correspondingly, the invention also discloses a method for supplying power by using a compatible ac/dc dual-channel power supply, which is applied to the above-mentioned circuit for supplying power by using a compatible ac/dc dual-channel power supply, and the method for controlling the circuit for supplying power by using a compatible ac/dc dual-channel power supply comprises the following steps:

when the alternating current power supply 60 supplies power normally, the alternating current power supply provided by the alternating current power supply 60 supplies power to the control unit, and the alternating current power supply is converted into a second direct current power by the AC-DC conversion unit 40 and then supplies power to the fan 80;

when the ac power supply 60 is abnormal, the fan 80 is supplied with power by the first dc power supplied from the dc power supply 70.

With reference to fig. 1 to 4, the main control unit 50 of the present invention can be connected to a DC power supply 70 through a DC input terminal 52 for supplying power, an AC input terminal 51 is electrically connected to an input terminal of the AC-DC conversion unit 40 and an AC power supply port 10, the AC-DC conversion unit 40 is configured to convert AC power into second DC power having a voltage consistent with that of the first DC power, and the first DC power and the second DC power are connected in parallel to supply power to a fan 80, which is compatible with AC-DC two-way power supply; on the other hand, after the alternating current is converted into the second direct current with the same voltage as the first direct current through the AC-DC conversion unit 40, the first direct current and the second direct current are connected in parallel and then supply power to the fan 80, so that the fan 80 can be kept in a power supply state, the fan 80 is prevented from being stopped due to failure of the alternating current power supply 60 or the direct current power supply 70, and safety accidents caused by low heat exchange efficiency due to untimely heat dissipation of the heat pipe due to the fact that the fan 80 is stopped are effectively prevented.

The above disclosure is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the scope of the present invention, therefore, the present invention is not limited by the appended claims.

Claims (10)

1. A compatible alternating current-direct current double-circuit power supply circuit is characterized in that: including alternating current power supply port, direct current power supply port, fan port, AC-DC conversion unit and main control unit, the alternating current power supply port is used for inserting alternating current power supply, the direct current power supply port is used for inserting direct current power supply, alternating current power supply is used for providing the alternating current, direct current power supply is used for providing first direct current, the fan port is used for the electricity to be connected, the main control unit is equipped with alternating current input end, direct current input end and load end, the main control unit accessible direct current input end inserts direct current power supply and supplies power, the load end is used for the electricity to connect the compressor, alternating current input end electricity respectively connect the AC-DC conversion unit the input with the alternating current power supply port, AC-DC conversion unit be used for with alternating current conversion to with the second direct current that the voltage of first direct current is unanimous, first direct current and second direct current are parallelly connected the back to the fan power supply.

2. The compatible ac-dc duplex power supply circuit of claim 1, wherein: the air switch is connected in series on a loop where the AC power supply port is located, and the DC air switch is connected in series on a loop where the DC power supply port is located.

3. The compatible ac-dc duplex power supply circuit of claim 1, wherein: still include the rectifier module, AC-DC conversion unit's output electricity is connected the first input of rectifier module, direct current power supply port electricity is connected the second input of rectifier module, rectifier module's output electricity is connected the fan port, rectifier module is used for connecting first direct current and second direct current after in parallel right the fan power supply.

4. The compatible ac-dc duplex power supply circuit of claim 3, wherein: the rectification module comprises a first diode, a second diode, a third diode and a fourth diode, wherein the cathode of the first diode is electrically connected with the anode of the second diode, the cathode of the third diode is electrically connected with the anode of the fourth diode, the anode of the first diode is connected with the anode of the third diode, the cathode of the second diode is electrically connected with the fan port after being connected with the cathode of the fourth diode, the direct-current power supply port is electrically connected between the cathode of the first diode and the anode of the second diode, and the output end of the AC-DC conversion unit is electrically connected between the cathode of the third diode and the anode of the fourth diode.

5. The compatible ac-dc duplex power supply circuit of claim 1, wherein: the control coil of the alternating current contactor is controlled by the first direct current, and when the direct current power supply port is connected with a direct current power supply, the normally closed contact of the voltage monitoring unit keeps normally closed, so that the control coil of the alternating current contactor is electrified, and the loop of the direct current power supply port is conducted; when the direct current power supply port is connected with the alternating current power supply by mistake, the normally closed contact of the voltage monitoring unit is disconnected, so that the control coil of the alternating current contactor is not electrified, and the loop where the direct current power supply port is located is disconnected.

6. The compatible ac-dc duplex power supply circuit of claim 1, wherein: the main control unit is also used for sampling the voltage of the fan and performing undervoltage and overvoltage protection on the fan.

7. The compatible ac-dc duplex power supply circuit of claim 6, characterized in that: the fan control circuit comprises a main control unit and a starting unit, wherein the main control unit is also provided with a fan control end used for being electrically connected with the PWM end, the starting unit comprises a PWM chip, a first starting resistor, a second starting resistor and a relay, the first starting resistor and the second starting resistor are sequentially connected in series to form a starting circuit, the resistance value of the first starting resistor is smaller than that of the second starting resistor, the second starting resistor is electrically connected with the input end of the PWM chip, the output end of the PWM chip is electrically connected with the fan control end, the relay and the second starting resistor are arranged in parallel, the relay is a normally open contact relay, a control coil of the relay is electrically connected with the main control unit, and when the input voltage is high voltage, the control coil of the relay is controlled not to be electrified so that the relay keeps disconnected; when the input voltage is low voltage, the control coil of the relay is controlled to be electrified so as to close the relay, and the starting circuit is equivalent to a circuit only provided with a first starting resistor.

8. The compatible ac-dc duplex power supply circuit of claim 1, wherein: the compressor is characterized by further comprising a driving unit for driving the compressor, wherein the input end of the driving unit is connected with the load end, and the output end of the driving unit is electrically connected with the compressor.

9. The compatible ac-dc duplex power supply circuit of claim 1, wherein: the voltage of alternating current is 220V, and the voltage of first direct current and second direct current is 48V.

10. A power supply method compatible with an AC/DC double-circuit power supply is characterized in that: the compatible alternating current-direct current dual-channel power supply circuit applied to any one of claims 1 to 9, wherein the compatible alternating current-direct current dual-channel power supply circuit control method comprises the following steps:

when the alternating current power supply supplies power normally, the control unit is powered by alternating current provided by the alternating current power supply, and the fan is powered after the alternating current is converted into second direct current by the AC-DC conversion unit;

when the alternating current power supply is abnormal, the first direct current provided by the direct current power supply supplies power to the fan.

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