WO2017219887A1

WO2017219887A1 - Power source circuit, and power source recovery control circuit and method

Info

Publication number: WO2017219887A1
Application number: PCT/CN2017/087902
Authority: WO
Inventors: 朱德强
Original assignee: 中兴通讯股份有限公司
Priority date: 2016-06-23
Filing date: 2017-06-12
Publication date: 2017-12-28
Also published as: CN107546838B; CN107546838A

Abstract

A power source circuit, and a power source recovery control circuit and method. During power failure recovery of an AC/DC power source, a sampling circuit (31) of the power source recovery control circuit performs sampling on outputs of the AC/DC power source; and when a control circuit (32) of the power source recovery control circuit determines, according to the sampling result, that an outputted voltage of the AC/DC power source is lower than an outputted voltage of a standby power source that currently supplies power, the control circuit (32) sets the outputted voltage of the AC/DC power source to a target voltage value higher than the outputted voltage of the standby power source (for example, a battery). In this way, the outputted voltage Vout of the power source can be normally established after a system has a a short time of power interruption, and seamless system power supply switchover of the active battery and the AC/DC power source can be implemented during the power failure recovery of the AC/DC power source. Compared with the existing oring circuit control mode, the power source circuit is simpler, has relatively lower costs, and does not significantly affect the efficiency of the power source.

Description

Power circuit, power recovery control circuit and method

Technical field

The present invention relates to the field of power supplies, and in particular, to a power supply circuit, a power recovery control circuit, and a method.

Background technique

Some communication systems for AC/DC communication power applications, such as switches, need to be equipped with batteries in some application scenarios to meet the requirements of certain services of the system for short-term power outages. On these systems, the battery charge and discharge management circuit can be integrated inside the communication power supply or integrated inside the system, as shown in Figure 1. In the system configuration of Figure 1, the output of the power supply is directly connected to the DC bus of the system. When the utility power is cut off, the charging management circuit in the system receives the AC power loss from the AC/DC power supply (hereinafter referred to as the power supply). The alarm signal is then closed by the control switch S1, which supplies power to the system. Since the action and recovery of the AC power-down alarm circuit is generally fast, after the utility power is restored, the battery charge and discharge management circuit can quickly detect that the AC power-down alarm signal returns to normal. At this time, if the switch S1 is immediately turned off, there is a possibility that the power supply The output voltage Vout has not been established, causing the system to be powered down for a short time.

In another case, after the system detects that the AC power-down alarm signal returns to normal, the switch S1 is turned off after a delay, but there is also a possibility that if the mains power-off time is short, the residual voltage of the battery will be higher than The output voltage set by the power supply is high. If the power output does not have an Oring circuit, when the utility power is restored, the PWM control chip inside the power supply starts to work, and the control loop of the power supply detects that the output of the power supply has a voltage (ie, the battery voltage), and is set by the power supply itself. The output voltage is high, then the PWM chip of the power supply will not be driven again, and the Vout voltage of the power supply itself cannot be established. In this case, even if the S1 is delayed, the system will be powered off for a short time because the power supply output voltage cannot be established immediately. On the contrary, if the power output in Figure 1 has an Oring circuit, after the mains recovery, the battery voltage will not affect the power supply output voltage Vout. After the system detects that the AC power-down alarm signal returns to normal, it can delay the time. Then switch S1 off, so that the battery and AC/DC power supply can supply power to the system. Sew switch. However, the current switching of the battery and the AC/DC power supply to the system is performed by the Oring circuit. In the embodiment of the present invention, another control scheme different from the Oring circuit is proposed to implement the battery and the AC/DC power supply. Seamless switching of system power.

Summary of the invention

The embodiment of the invention provides a power circuit, a power restoration control circuit and a method for solving the seamless switching of the battery and the AC/DC power supply to the system during the AC/DC power failure recovery process.

A power recovery control circuit according to an embodiment of the present invention includes a sampling circuit and a control circuit; the sampling circuit is respectively connected to an AC/DC power output end and the control circuit input end; the control circuit output end and the AC/DC Power control terminal connection;

The sampling circuit is configured to sample an output of the AC/DC power supply during an AC/DC power failure recovery process;

The control circuit is configured to set an output voltage set by the AC/DC power source to be greater than the standby when determining that the output voltage of the AC/DC power source is lower than a current power supply standby power output voltage according to the sampling result The target voltage value of the power supply output voltage.

Optionally, the control circuit is further configured to: when determining, according to the sampling result, that an output voltage of the AC/DC power source is higher than a current power supply standby power output voltage, setting an output voltage of the AC/DC power source by The target voltage value is adjusted back to a normal output voltage value.

Optionally, the sampling circuit includes a main sampling circuit and a auxiliary sampling circuit; the main sampling circuit includes a first main divided voltage collecting sub-circuit and a second main divided voltage collecting sub-circuit in series, the first main divided voltage The acquisition sub-circuit is connected to the main circuit output of the flyback transformer of the AC/DC power supply, and the second main voltage division sub-circuit is grounded; the auxiliary sampling circuit includes a first auxiliary voltage division acquisition circuit and a second auxiliary sub-series in series a voltage collecting sub-circuit, the first auxiliary main voltage dividing circuit is connected with a secondary output of a flyback transformer of an AC/DC power source, the second auxiliary voltage dividing sub-circuit is grounded; and the second main voltage dividing collector is The circuit and the second auxiliary voltage dividing sub-circuit are connected by a single-conducting circuit, and when the voltage of the second main-dividing sub-circuit is higher than the second auxiliary voltage-dividing sub-circuit, the single-conductor The circuit is turned on; the voltage of the second main voltage dividing sub-circuit is the An output voltage of the output end of the sample circuit; the control circuit includes a comparison circuit, wherein two input ends of the comparison circuit are respectively connected to the output end of the sampling circuit and the reference voltage Vref, and the output voltage of the sampling circuit and the reference voltage Vref Comparing, when the reference voltage is less than the reference voltage, determining that the output voltage of the AC/DC power supply is lower than the current power supply standby power output voltage, and transmitting the boost voltage control signal to the AC/DC power supply control terminal.

Optionally, the relationship between the resistance R1 of the first main voltage dividing sub-circuit, the resistance R2 of the second main voltage dividing sub-circuit, the resistance R4 of the second auxiliary voltage dividing circuit, and the reference voltage Vref is as follows:

The Vbat is the standby power output voltage; the Vref is equal to the output voltage of the AC/DC power supply multiplied by

The R2//R4 is the resistance of the resistors R2 and R4 in parallel.

Optionally, the sampling circuit includes a main sampling circuit and a auxiliary sampling circuit; the main sampling circuit includes a first main divided voltage collecting sub-circuit and a second main divided voltage collecting sub-circuit in series, the first main divided voltage collecting The sub-circuit is connected to the main circuit output of the power transformer of the AC/DC power supply, the second main voltage dividing sub-circuit is grounded; the voltage of the second main voltage dividing sub-circuit is the output voltage of the output end of the sampling circuit; The auxiliary sampling circuit includes a current collector, a voltage matching sub-circuit, and a switch control sub-circuit, wherein the current collector is connected in series with a load on a main circuit output of the power transformer of the AC/DC power source, and the voltage matching sub-circuit and the The second main voltage dividing sub-circuit is connected in parallel, and the voltage matching circuit is provided with a shutdown switch; the input end of the switch control sub-circuit is respectively connected with the current collector and the switch reference voltage, and the output end is connected with the shutdown switch Comparing the current collector with a switch reference voltage, when the switch reference voltage is less than the switch reference voltage, turning off the off; the control circuit includes a comparison circuit, the ratio The two input terminals of the comparison circuit are respectively connected to the sampling circuit output end and the reference voltage Vref, and compare the output voltage of the sampling circuit with the reference voltage Vref, and when the reference voltage is smaller than the reference voltage, determine the AC/DC power supply. Output The voltage is lower than the currently supplied standby power supply output voltage, and a boost voltage control signal is sent to the AC/DC power supply control terminal.

Optionally, the relationship between the resistor R11 of the first main voltage dividing sub-circuit, the resistor R21 of the second main voltage dividing sub-circuit, the resistor R31 of the voltage matching sub-circuit, and the reference voltage Vref is as follows:

The R21//R31 is a resistance in which the resistors R21 and R31 are connected in parallel.

Optionally, the backup power source is a battery.

Another embodiment of the present invention provides a power supply circuit including an AC/DC power supply, a backup power supply, and a power recovery control circuit as described above;

The standby power source is connected to the output end of the AC/DC power source, and is configured to supply power to the load when the AC/DC power source is powered off;

The power recovery control circuit is configured to sample an output of the AC/DC power supply during an AC/DC power failure recovery process, and determine, according to the sampling result, an output voltage of the AC/DC power supply that is greater than a current power supply standby power output voltage. When low, the output voltage set by the AC/DC power source is set to a target voltage value greater than the standby power supply output voltage.

Another embodiment of the present invention provides a power restoration control method, including:

The output of the AC/DC power supply is sampled during the AC/DC power failure recovery process;

And determining, according to the sampling result, that the output voltage of the AC/DC power source is lower than a current power supply standby power output voltage, and setting an output voltage of the AC/DC power source to be greater than a target voltage value of the standby power supply output voltage.

Optionally, the method further includes: setting, according to the sampling result, that the output voltage of the AC/DC power source is higher than a current power supply standby power output voltage, setting an output voltage callback set by the AC/DC power source to a normal state. Output voltage value.

According to still another embodiment of the present invention, there is also provided a storage medium comprising a stored program, wherein the program is executed to perform the method of any of the above.

According to still another embodiment of the present invention, there is also provided a processor for running a program, wherein the program is executed to perform the method of any of the above.

One of the above technical solutions has the following beneficial effects:

The sampling circuit of the power recovery control circuit samples the output of the AC/DC power supply during the AC/DC power failure recovery process, and the control circuit of the power recovery control circuit determines the output voltage of the AC/DC power supply to be compared with the current power supply according to the sampling result. When the standby power output voltage is low, the output voltage set by the AC/DC power supply is set to be larger than the target voltage value of the output voltage of the standby power source (for example, backup battery power source, etc.). This can ensure that the power supply output voltage is higher than the current battery voltage, and the output voltage Vout of the power supply is normally established, thereby achieving seamless switching of the backup battery and the AC/DC power supply to the system during the AC/DC power failure recovery process. Compared with the existing oring circuit control mode, the solution provided by the embodiment of the present invention is simpler, the cost is relatively lower, and has no significant effect on the efficiency of the power supply.

DRAWINGS

Figure 1 is a block diagram of a power supply circuit system with a backup battery;

2 is a schematic flowchart of a control method for power failure recovery according to a first embodiment of the present invention;

3 is a schematic structural diagram of a power restoration control circuit according to a first embodiment of the present invention;

4 is a schematic diagram of fluctuations in output voltage of an AC/DC power supply according to a first embodiment of the present invention;

FIG. 5 is a schematic diagram showing an alternative specific structure of the sampling circuit of FIG. 3; FIG.

6 is a schematic diagram 1 of an alternative specific structure of the sampling circuit of FIG. 5;

7 is a second schematic diagram of an alternative structure of the sampling circuit of FIG. 5;

FIG. 8 is a schematic structural diagram 1 of a power restoration control circuit according to a second embodiment of the present invention; FIG.

FIG. 9 is a schematic structural diagram 2 of a power restoration control circuit according to a second embodiment of the present invention.

detailed description

The technical solutions in the embodiments of the present invention are clearly and completely described in the following with reference to the accompanying drawings in the embodiments of the present invention. It is obvious that the described embodiments are only a part of the embodiments of the present invention, but not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative efforts are within the scope of the present invention.

Embodiment 1:

The control of the power-off recovery of the AC/DC power supply in this embodiment is implemented by the control process shown in FIG. 2:

S201: sampling the output of the AC/DC power supply during the AC/DC power failure recovery process;

In this step, at least one of the voltage and current of the output of the AC/DC power source may be specifically sampled. The circuit and sampling rules used for specific sampling can be flexibly set according to the actual application scenario.

S202: Determine, according to the sampling result, whether an output voltage of the AC/DC power source is lower than a current output voltage of the standby power supply, and if yes, go to S203; otherwise, go to S204.

S203: Set an output voltage set by the AC/DC power source to a target voltage value greater than a standby power supply output voltage. This can ensure that the output voltage of the AC/DC power supply is higher than the voltage of the currently-powered standby power supply, and the driving chip of the power supply normally outputs a driving signal, so that the power supply is turned on and the output voltage Vout is normally established.

S204: Set the output voltage callback set by the AC/DC power source to the normal output voltage value. During the AC/DC power failure recovery process, the output voltage of the AC/DC power supply fluctuates repeatedly. When it is detected again through S201 that the output voltage of the AC/DC power supply is lower than the output voltage of the currently supplied standby power supply, then it is transferred to S203 resets the output voltage set by the AC/DC power supply to be greater than The target voltage value of the standby power supply output voltage. This starts a process in which the power supply output voltage fluctuates repeatedly around the standby power supply voltage until the power supply switch of the standby power supply voltage is disconnected, all system loads are borne by the AC/DC power supply, and the AC/DC power supply output voltage no longer fluctuates, returning to Normal value. This enables seamless switching of the backup battery and AC/DC power supply to the system during AC/DC power failure recovery.

For a better understanding of the present invention, the control process illustrated in FIG. 2 is exemplified in conjunction with a power recovery control circuit. However, it should be understood that all circuit configurations capable of implementing the control process shown in FIG. 2 are within the scope of the present invention and are not limited to the circuit configurations shown below in this embodiment.

Referring to FIG. 3, the power restoration control circuit in this embodiment includes a sampling circuit 31 and a control circuit 32. The sampling circuit 31 is respectively connected to an AC/DC power output terminal and a control circuit input terminal; the control circuit output terminal and the AC /DC power control terminal (not shown) is connected;

The sampling circuit 31 is configured to sample the output of the AC/DC power supply during the AC/DC power failure recovery process;

The control circuit 32 is configured to set the output voltage set by the AC/DC power source to be greater than the target voltage of the standby power supply output voltage when determining that the output voltage of the AC/DC power supply is lower than the currently supplied standby power supply output voltage according to the sampling result of the sampling circuit. value. This can ensure that the output voltage of the AC/DC power supply is higher than the voltage of the currently-powered standby power supply, and the driving chip of the power supply normally outputs a driving signal, so that the power supply is turned on and the output voltage Vout is normally established. The backup power source in this embodiment may be various battery power sources.

When the control circuit 32 determines that the output voltage of the AC/DC power supply is higher than the currently supplied standby power supply output voltage according to the sampling result, the output voltage set by the AC/DC power supply is adjusted from the target voltage value to the normal output voltage value.

During the AC/DC power failure recovery process, the output voltage of the AC/DC power supply fluctuates repeatedly. When the control circuit 32 detects again that the output voltage of the AC/DC power supply is lower than the current output power of the standby power supply through the sampling result. , the output voltage set by the AC/DC power supply is reset to a target voltage value greater than the standby power output voltage. Thus the control circuit 32 can be sampled according to As a result, the output voltage of the AC/DC power supply is controlled to fluctuate repeatedly around the standby power supply voltage, as shown in FIG. Until the power supply switch of the standby power supply voltage is disconnected, all system loads are borne by the AC/DC power supply, and the AC/DC power supply output voltage no longer fluctuates and returns to the normal value.

The sampling circuit 31 in the embodiment may specifically sample at least one of an output voltage and a current of the AC/DC power source. The circuit and sampling rules used for specific sampling can be flexibly set according to the actual application scenario. For example, referring to FIG. 5, the sampling circuit 31 may specifically include a main sampling circuit 311 and a sub-sampling circuit 312. The main sampling circuit 311 can be specifically configured to sample the output voltage of the AC/DC power supply, and the auxiliary sampling circuit 312 can specifically sample the output voltage or current of the AC/DC power supply, and adjust the main sampling circuit 311 according to the sampling result. Output. The following is an example of sampling the output voltage or current of the AC/DC power supply by the auxiliary sampling circuit 312 as an example.

Referring to FIG. 6, the main sampling circuit 311 in this example includes a first main divided voltage collecting sub-circuit 3111 and a second main divided collecting sub-circuit 3112 connected in series, and a first main divided voltage collecting sub-circuit 3111 and AC/. The main circuit output connection of the flyback transformer of the DC power source, the second main voltage dividing sub-circuit 3112 is grounded; the main output voltage of the flyback transformer is the AC/DC power supply output voltage.

The auxiliary sampling circuit 312 includes a first auxiliary voltage dividing circuit 3121 and a second auxiliary voltage dividing sub circuit 3122 connected in series, and the first auxiliary main voltage dividing circuit 3121 is connected with the auxiliary circuit output of the flyback transformer of the AC/DC power source, The second auxiliary voltage dividing sub-circuit is grounded 3122;

The second auxiliary voltage dividing sub-circuit 3122 and the second main voltage dividing sub-circuit 3112 are connected by a single-conduction circuit, and the second main voltage-dividing sub-circuit 3112 is higher than the second auxiliary-dividing sub-circuit 3122. The single-conduction conduction circuit is turned on, and the second auxiliary voltage-dividing sub-circuit 3122 is connected in parallel with the second main-dividing collection sub-circuit 3112. The voltage of the second main voltage dividing sub-circuit 3112 is the output voltage of the output end of the sampling circuit, and is input to the comparison circuit of the control circuit 32.

The control circuit 32 includes a comparison circuit 321, and the two input terminals of the comparison circuit 321 are respectively connected to the output end of the sampling circuit 31 (i.e., point A of the second main voltage division sub-circuit 3112) and the reference voltage Vref. The comparison circuit 321 compares the output voltage of the sampling circuit 31 with the reference voltage Vref, and when it is smaller than the reference voltage, determines that the output voltage of the AC/DC power supply is lower than the currently supplied standby power supply. The output voltage is low, and the boost voltage control signal is sent to the AC/DC power supply control terminal, and the output voltage set by the AC/DC power supply is set as the target voltage value. Conversely, it is determined that the output voltage of the AC/DC power supply is higher than the output voltage of the currently supplied standby power supply, and the feedback voltage control signal is sent to the AC/DC power supply control terminal, and the output voltage set by the AC/DC power supply is called back from the target voltage value. Is the normal output voltage value.

In Figure 6, the secondary winding of the flyback transformer is used to provide the auxiliary power required by the secondary control circuit of the power supply. In this embodiment, a filter capacitor may also be disposed in the main path output and the auxiliary path output for filtering processing.

The unidirectional conduction circuit in this embodiment can be implemented by various components capable of implementing unidirectional conduction control, such as a diode. In this case, the anode of the diode is connected to point A, and the cathode is connected to point B.

After the short-term power failure and recovery of the mains, when the AC/DC power supply is turned on, the backup battery voltage has been added to the main circuit output, but the auxiliary circuit output voltage is not established at this time, so the voltage at point B is lower than the voltage at point A, single guide The circuit is turned on, the second auxiliary voltage dividing sub-circuit 3122 is connected in parallel with the second main voltage dividing sub-circuit 3112, so that the voltage obtained at point A is lower than the reference Vref voltage, and the boost voltage control signal is sent to output the AC/DC power supply voltage. Set to a target voltage value higher than the battery voltage, the power supply PWM chip outputs a drive signal, and the main circuit output is established.

Before the main circuit output voltage is lower than the battery voltage, the output voltage of the auxiliary circuit is lower because the main circuit output is not loaded. In the parameter design, the voltage at point B is lower than the voltage at point A, and the one-way conduction circuit is turned on. In order to ensure that the main circuit output voltage is greater than the backup battery voltage when the power is turned on, the resistance R1 of the first main voltage dividing sub-circuit, the resistance R2 of the second main voltage dividing sub-circuit, and the resistance R4 of the second auxiliary voltage dividing circuit are set. , the relationship between R1, R2, R4 and the reference voltage Vref must meet the following formula:

Vbat is the standby power supply output voltage; Vref is equal to the output voltage of the AC/DC power supply multiplied by

R2//R4 is the resistance of the resistors R2 and R4 in parallel.

Thus, when the AC/DC power supply is normally turned on, the main circuit output voltage is greater than the backup battery voltage, and the main circuit output of the power supply is loaded. At this time, the auxiliary circuit voltage rises, the voltage at point B is higher than the voltage at point A, and the single-conduction circuit is turned off. When the main circuit output voltage satisfies the following relationship, it is lower than the backup battery voltage.

At this time, because the main circuit voltage is lower than the battery voltage, the main circuit output is not loaded, the auxiliary circuit output voltage is lowered, and the single-conduction circuit is re-conducted, and the first main voltage dividing sub-circuit 3121 is further involved in the sampling network of the main circuit output. , causing the main circuit output voltage to rise, higher than the battery voltage and then loaded again. This begins a repetitive process in which the mains output voltage is constantly fluctuating around the battery voltage until the switch S1 in Figure 1 is opened, disengaging the backup battery from the DC bus on the system. At this time, due to the AC/DC power supply, the auxiliary circuit output voltage is high, the one-way conduction circuit is cut off, and the main circuit output returns to the normal voltage.

Please refer to FIG. 7, which shows a specific structure of another sampling circuit of the embodiment.

The main sampling circuit 311 includes a first main voltage dividing sub-circuit 3111 and a second main voltage dividing sub-circuit 3112 connected in series, and the first main voltage dividing sub-circuit 3111 is connected to the main circuit output of the power transformer of the AC/DC power source. The second main voltage dividing sub-circuit 3112 is grounded;

The auxiliary sampling circuit 312 includes a current collector 31211, a voltage matching sub-circuit 31213, and a switch control sub-circuit 31212. The current collector 31211 is connected in series with the load on the main circuit output of the power transformer of the AC/DC power source, and the voltage matching sub-circuit 31213 and the second The main voltage dividing sub-circuit 3112 is connected in parallel, and the voltage matching circuit is provided with a shutdown switch; the input end of the switch control sub-circuit 31212 is respectively connected with the current collector 31211 and the switch reference voltage, and the output end is connected with the shutdown switch, which collects current. When compared with the switch reference voltage, when compared with the switch reference voltage, the switch is turned off and closed, and the voltage matching sub-circuit 31213 is connected in parallel with the second main divided voltage collecting sub-circuit 3112. Point A in Figure 7 is still the output of sampling circuit 31.

The control circuit includes a comparison circuit 321, and the two input ends of the comparison circuit 321 are respectively connected with the output end of the sampling circuit 31 and the reference voltage Vref, and compare the output voltage of the sampling circuit 31 with the reference voltage Vref, which is smaller than the reference voltage, and determines the AC/DC. The output voltage of the power supply is higher than the current supply The standby power output voltage is low, and the boost voltage control signal is sent to the AC/DC power supply control terminal, and the output voltage set by the AC/DC power supply is set to the target voltage value. Conversely, it is determined that the output voltage of the AC/DC power supply is higher than the output voltage of the currently supplied standby power supply, and the feedback voltage control signal is sent to the AC/DC power supply control terminal, and the output voltage set by the AC/DC power supply is called back from the target voltage value. Is the normal output voltage value.

After the mains recovery after power failure, the AC/DC power supply output has not been established. At this time, the power supply output current is zero, and the switch control sub-circuit 31212 controls the turn-off switch to be turned on, so that the voltage obtained at point A is lower than the Vref voltage, and the power supply PWM chip The drive signal is output and the main output is established.

Before the main circuit output voltage is lower than the battery voltage, the shutdown switch is always on because the main circuit output is not loaded. In order to ensure that the output voltage is greater than the backup battery voltage when the power is turned on, the resistor R11 of the first main voltage dividing sub-circuit, the resistor R21 of the second main voltage dividing sub-circuit, the resistor R31 of the voltage matching sub-circuit, and the reference voltage Vref The relationship needs to ensure that the following relationship is established:

In the above formula, Vbat is the standby power (battery) output voltage; Vref is equal to the output voltage of the AC/DC power supply multiplied by

R21//R31 is the resistance of the resistors R21 and R31 in parallel.

Thus, when the power supply is normally turned on, the output voltage of the main circuit is greater than the battery voltage, and the main circuit output of the power supply is loaded. At this time, the switch control sub-circuit 31212 controls the shutdown switch to be turned off. At this time, the output voltage of the main circuit satisfies the following relationship, which is lower than battery voltage.

At this time, because the main circuit voltage is lower than the backup battery voltage, the main circuit output is not loaded, and the shutdown switch is re-conducted, and the voltage matching sub-circuit 31213 participates in the sampling network of the main circuit output, causing the main circuit output voltage to rise, which is high. Loaded again after the battery voltage. This begins a repetitive process in which the mains output voltage is constantly fluctuating around the backup battery voltage until the switch S1 in Figure 1 is opened, disengaging the backup battery from the DC bus on the system. At this time, due to the power supply, the shutdown switch is turned off, and the main circuit output returns to the normal voltage.

Based on the power recovery control circuit described above, the embodiment further provides a power supply circuit including an AC/DC power supply, a backup power supply, and a power restoration control circuit as described above;

The backup power supply is connected to the AC/DC power supply output, and is set to supply power to the load when the AC/DC power supply is powered off; the power recovery control circuit is set to perform the output of the AC/DC power supply during the AC/DC power failure recovery process. Sampling, according to the sampling result, when the output voltage of the AC/DC power supply is lower than the output voltage of the currently supplied standby power supply, the output voltage set by the AC/DC power supply is set to be greater than the target voltage value of the standby power supply output voltage. According to the sampling result, when the output voltage of the AC/DC power supply is higher than the output voltage of the currently supplied standby power supply, the output voltage callback set by the AC/DC power supply is set to the normal output voltage value. During the AC/DC power failure recovery process, the power recovery control circuit controls the power supply output voltage to fluctuate repeatedly around the standby power supply voltage until the power supply switch of the standby power supply voltage is disconnected, and all system loads are borne by the AC/DC power supply, AC/DC. The power supply output voltage no longer fluctuates and returns to normal. This enables seamless switching of the backup battery and AC/DC power supply to the system during AC/DC power failure recovery.

Embodiment 2:

For a better understanding of the present invention, the solutions of the embodiments of the present invention are further illustrated by two specific circuit configurations.

Referring to the structure diagram of the power control circuit shown in FIG. 8, the figure shows a specific circuit structure diagram corresponding to the control block diagram shown in FIG. 6. The first main voltage dividing sub-circuit 3111 and the second main voltage dividing sub-circuit 3112 are respectively R1 and R2, and the first auxiliary voltage dividing circuit 3121 and the second auxiliary voltage dividing sub-circuit 3122 are respectively R3 and R4. The single conduction circuit is diode VD1 and the auxiliary power supply is SVCC. The comparison circuit 321 is implemented using a voltage error amplifier.

The structure shown in Figure 8 is typically applied to the topology of a flyback transformer. In the figure, the main circuit output refers to the power output loop of the transformer (ie, the voltage output from the power supply to the system). There is also an auxiliary winding on the flyback transformer (the output is the auxiliary output), which is used to provide the secondary control circuit of the power supply. Auxiliary power supply SVCC. Capacitors C1 and C2 are filter capacitors for the main and auxiliary outputs, respectively.

The main circuit output voltage is divided and sampled by R1 and R2 resistors and sent to the voltage error amplifier. The auxiliary winding output is divided by the resistors R3 and R4, and then connected to the cathode of the diode VD1, VD1 The anode is connected to a point intermediate R1 and R2.

The auxiliary winding output of the flyback transformer has a characteristic that when the main circuit output is loaded, the auxiliary circuit output voltage is higher than when the main circuit output is no load. This example is the difference between the output voltage of the auxiliary circuit under different conditions of the main line output load and no load.

After the short-term power outage and recovery of the mains, when the AC/DC power supply is turned on, the battery voltage has been added to the main circuit output, but at this time, the auxiliary circuit output voltage is not established, so the voltage at point B is lower than the voltage at point A, and the diode VD1 leads. Pass, the resistor R4 and the resistor R2 are connected in parallel, so that the voltage obtained at the point A is lower than the Vref voltage, the power PWM chip outputs the driving signal, and the main circuit output is established.

Before the main circuit output voltage is lower than the battery voltage, the output voltage of the auxiliary circuit is lower because the main circuit output is not loaded. In the parameter design, the voltage at point B is lower than the voltage at point A, and VD1 is turned on. In order to ensure that the output voltage is greater than the battery voltage when the power is turned on, the following parameters must be established in the parameter design. In the following relationship, R2//R4 represents the resistance of R2 and R4 in parallel.

In this way, when the power supply is normally turned on, the output voltage of the main circuit is greater than the battery voltage, and the main circuit output of the power supply is loaded. At this time, the auxiliary winding voltage rises, the voltage at point B is higher than the voltage at point A, and the diode VD1 is turned off. At this time, the output voltage of the main circuit is satisfied. The following relationship is lower than the battery voltage.

At this time, because the main circuit voltage is lower than the battery voltage, the main circuit output is not loaded, the auxiliary circuit output voltage is lowered, the diode VD1 is turned on again, and R4 participates in the sampling network of the main circuit output, causing the main circuit output voltage to rise, higher than The battery voltage is again loaded. This begins a repetitive process in which the mains output voltage is constantly fluctuating around the battery voltage until the switch S1 in Figure 1 is opened, disengaging the battery from the DC bus on the system. At this time, due to the power supply, the auxiliary circuit output voltage is high, the VD1 diode is turned off, and the main circuit output returns to the normal voltage.

Referring to the structure of the power control circuit shown in FIG. 9, the figure shows a specific circuit structure diagram corresponding to the control block diagram shown in FIG. The first main voltage dividing sub-circuit 3111 and the second main voltage dividing sub-circuit 3112 are respectively R11 and R21, and the current collector 31211 is R (lsence), the voltage matching sub-circuit 31213 is R31, the switch control sub-circuit 31212 is a comparator or an operational amplifier, the turn-off switch is a triode VT1, the switch reference voltage is V (lref), and the comparison circuit 321 is implemented by a voltage error amplifier.

After the mains recovery after power failure, the AC/DC power supply output has not been established. At this time, the power supply output current is zero, and the current detection op amp or comparator controls VT1 to be turned on, so that the voltage obtained at point A is lower than the Vref voltage, and the power supply PWM chip The drive signal is output and the main output is established.

Before the main circuit output voltage is lower than the battery voltage, VT1 is always on because the main circuit output is not loaded. In order to ensure that the output voltage is greater than the battery voltage when the power is turned on, the following parameters must be established in the parameter design. In the following relationship, R21//R31 represents the resistance of R21 and R31 in parallel.

In this way, when the power supply is normally turned on, the output voltage of the main circuit is greater than the battery voltage, and the main circuit output of the power supply is loaded. At this time, the current detecting op amp or the comparator controls VT1 to be turned off. At this time, the output voltage of the main circuit satisfies the following relationship, which is lower than battery voltage.

At this time, because the main circuit voltage is lower than the battery voltage, the main circuit output is not loaded, VT1 is re-conducted, and R3 participates in the sampling network of the main circuit output, causing the main circuit output voltage to rise, and the load is higher than the battery voltage. . This begins a repetitive process in which the mains output voltage is constantly fluctuating around the battery voltage until the switch S1 in Figure 1 is opened, disengaging the battery from the DC bus on the system. At this time, due to the power supply, VT1 is turned off, and the main circuit output returns to normal voltage.

The solution of the embodiment of the present invention realizes seamless switching of the backup battery and the AC/DC power supply to the system during the AC/DC power failure recovery process, which is simpler than the existing oring circuit control method, and the cost is relatively more. Low and has no significant effect on the efficiency of the power supply.

Embodiments of the present invention also provide a storage medium including a stored program, wherein the program described above executes the method of any of the above.

Optionally, in the embodiment, the foregoing storage medium may include, but is not limited to, a USB flash drive, a Read-Only Memory (ROM), and a Random Access Memory (RAM). A variety of media that can store program code, such as a hard disk, a disk, or an optical disk.

Embodiments of the present invention also provide a processor for running a program, wherein the program is executed to perform the steps of any of the above methods.

It will be apparent to those skilled in the art that the various modules or steps of the present invention described above can be implemented by a general-purpose computing device that can be centralized on a single computing device or distributed across a network of multiple computing devices. Alternatively, they may be implemented by program code executable by the computing device such that they may be stored in the storage device by the computing device and, in some cases, may be different from the order herein. The steps shown or described are performed, or they are separately fabricated into individual integrated circuit modules, or a plurality of modules or steps thereof are fabricated as a single integrated circuit module. Thus, the invention is not limited to any specific combination of hardware and software.

The above is only a specific embodiment of the present invention, and is not intended to limit the present invention in any way. Any simple modification, equivalent change, combination or modification of the above embodiments in accordance with the technical spirit of the present invention is still in the present invention. The scope of protection of the technical solution of the invention.

Industrial applicability

As described above, the power supply circuit and the power recovery control circuit and method provided by the embodiments of the present invention have the following beneficial effects: the power supply output voltage Vout can be normally established after the system is powered off for a short period of time, and the AC/DC power supply is broken. During the electrical recovery process, the backup battery and the AC/DC power supply seamlessly switch the power supply to the system. Compared with the existing oring circuit control mode, the solution provided by the embodiment of the present invention is simpler, the cost is relatively lower, and has no significant effect on the efficiency of the power supply.

Claims

A power recovery control circuit includes a sampling circuit and a control circuit; the sampling circuit is respectively connected to an AC/DC power output end and the control circuit input end; and the control circuit output end is connected to an AC/DC power supply control end;

The sampling circuit is configured to sample an output of the AC/DC power supply during an AC/DC power failure recovery process;

The control circuit is configured to set an output voltage set by the AC/DC power source to be greater than the standby when determining that the output voltage of the AC/DC power source is lower than a current power supply standby power output voltage according to the sampling result The target voltage value of the power supply output voltage.
The power restoration control circuit according to claim 1, wherein said control circuit is further configured to: when said output voltage of said AC/DC power supply is higher than a current power supply output voltage of said current power supply based on said sampling result, said AC The output voltage set by the /DC power supply is adjusted back to the normal output voltage value by the target voltage value.
The power recovery control circuit according to claim 1 or 2, wherein said sampling circuit comprises a main sampling circuit and a secondary sampling circuit;

The main sampling circuit includes a first main divided voltage collecting sub-circuit and a second main divided voltage collecting sub-circuit connected in series, and the first main divided voltage collecting sub-circuit is connected with a main output of the flyback transformer of the AC/DC power supply. The second main voltage dividing sub-circuit is grounded;

The auxiliary sampling circuit includes a first auxiliary voltage dividing circuit and a second auxiliary voltage dividing sub-circuit connected in series, and the first auxiliary main voltage dividing circuit is connected with the auxiliary circuit output of the flyback transformer of the AC/DC power source. The second auxiliary voltage dividing sub-circuit is grounded;

The second main voltage dividing sub-circuit and the second auxiliary voltage dividing sub-circuit are connected by a single-conducting circuit, and the second main-dividing sub-circuit voltage is higher than the second auxiliary voltage When the sub-circuit is collected, the single-conduction conduction circuit is turned on; the voltage of the second main-divided-collection sub-circuit is an output voltage of the output end of the sampling circuit;

The control circuit includes a comparison circuit, and the two inputs of the comparison circuit are respectively The output end of the sampling circuit is connected to the reference voltage Vref, and the output voltage of the sampling circuit is compared with the reference voltage Vref. When the reference voltage is smaller than the reference voltage, the output voltage of the AC/DC power supply is determined to be higher than the current power supply standby power output. The voltage is low and a boost voltage control signal is sent to the AC/DC power control terminal.
The power recovery control circuit according to claim 3, wherein the resistor R1 of the first main voltage dividing sub-circuit, the resistor R2 of the second main voltage dividing sub-circuit, and the resistor R4 of the second auxiliary voltage dividing circuit And the relationship of the reference voltage Vref is as follows:

The Vbat is the standby power output voltage; the Vref is equal to the output voltage of the AC/DC power supply multiplied by
The R2//R4 is the resistance of the resistors R2 and R4 in parallel.
The power recovery control circuit according to claim 1 or 2, wherein said sampling circuit comprises a main sampling circuit and a secondary sampling circuit;

The main sampling circuit includes a first main divided voltage collecting sub-circuit and a second main divided voltage collecting sub-circuit connected in series, and the first main divided voltage collecting sub-circuit is connected with a main circuit output of a power transformer of an AC/DC power supply, The second main voltage dividing sub-circuit is grounded; the voltage of the second main voltage dividing sub-circuit is an output voltage of the output end of the sampling circuit;

The auxiliary sampling circuit includes a current collector, a voltage matching sub-circuit, and a switch control sub-circuit, wherein the current collector is connected in series with a load on a main circuit output of the power transformer of the AC/DC power source, and the voltage matching sub-circuit and the The second main voltage dividing sub-circuit is connected in parallel, and the voltage matching circuit is provided with a shutdown switch; the input end of the switch control sub-circuit is respectively connected with the current collector and the switch reference voltage, and the output end is connected with the shutdown switch Comparing the current collector with the switch reference voltage, when the switch is lower than the switch reference voltage, turning off and closing the switch;

The control circuit includes a comparison circuit, and two input ends of the comparison circuit are respectively connected to the sampling circuit output end and the reference voltage Vref, and the output voltage of the sampling circuit is compared with the reference voltage Vref, which is smaller than the reference voltage. And determining that the output voltage of the AC/DC power source is lower than the currently-powered standby power supply output voltage, and transmitting a boost voltage control signal to the AC/DC power supply control end.
The power recovery control circuit according to claim 5, wherein the resistor R11 of the first main voltage dividing sub-circuit, the resistor R21 of the second main voltage dividing sub-circuit, the resistor R31 of the voltage matching sub-circuit, and the The relationship of the reference voltage Vref is as follows:

The Vbat is the standby power output voltage; the Vref is equal to the output voltage of the AC/DC power supply multiplied by
The R21//R31 is a resistance in which the resistors R21 and R31 are connected in parallel.
The power recovery control circuit according to claim 1 or 2, wherein said backup power source is a battery.
A power supply circuit comprising an AC/DC power supply, a backup power supply, and a power recovery control circuit according to any one of claims 1-7;

The standby power source is connected to the output end of the AC/DC power source, and is configured to supply power to the load when the AC/DC power source is powered off;

The power recovery control circuit is configured to sample an output of the AC/DC power supply during an AC/DC power failure recovery process, and determine, according to the sampling result, an output voltage of the AC/DC power supply that is greater than a current power supply standby power output voltage. When low, the output voltage set by the AC/DC power source is set to a target voltage value greater than the standby power supply output voltage.
A power recovery control method includes:

The output of the AC/DC power supply is sampled during the AC/DC power failure recovery process;

And determining, according to the sampling result, that the output voltage of the AC/DC power source is lower than a current power supply standby power output voltage, and setting an output voltage of the AC/DC power source to be greater than a target voltage value of the standby power supply output voltage.
The power restoration control method of claim 9, further comprising:

When it is determined according to the sampling result that the output voltage of the AC/DC power source is higher than the current power supply standby power output voltage, the output voltage callback set by the AC/DC power source is set to a normal output voltage value.
A storage medium, characterized in that the storage medium comprises a stored program, wherein the program is executed to perform the method of any one of claims 9 to 10.