Power control device and power control method

Abstract

The invention discloses a power control device and a power control method. The power control device comprises a power conversion unit which is provided with a primary side circuit and a secondary side circuit which are connected through a transformer, and the power conversion unit is configured to convert an alternating current input voltage of an alternating current power supply and then output the converted alternating current input voltage to a load; and a control unit configured to control the actual output power output to the load not to exceed a maximum power limit according to a temperature signal and an input voltage signal, the maximum power limit is the smaller one of a first maximum power value related to the temperature signal and a second maximum power value related to the input voltage signal. According to the invention, the output power can be released to the greatest extent according to different input voltages in combination with the actual detection temperature.

Description

Technical Field

[0001] The present invention relates to a power electronics technology, and in particular to a power control device and a power control method. Background Art

[0002] The energy lost by a power adapter during operation is mainly dissipated in the form of heat, and usually relies on natural heat dissipation under windless conditions. The level of its power transmission efficiency directly determines its actual temperature rise. In order to accommodate the mains voltage input globally, the power adapter usually needs to consider an input voltage range of 90 - 264 Vac during design. Depending on the topology used inside the power adapter, the transmission efficiency of the power adapter varies under different AC input voltages. The design of the rated power often takes the maximum transmission power that can be continuously operated under the worst heat dissipation conditions as a reference, which greatly limits the maximum power output capacity under other better heat dissipation conditions.

[0003] Taking the common single - stage Flyback scheme as an example, conduction loss dominates under rated output. The operating efficiency of the power supply is higher under high - voltage input than under low - voltage input. 90 Vac input often corresponds to the worst heat dissipation conditions, which also indirectly determines the maximum output power at which the power adapter can operate stably for a long time. The heat dissipation conditions under 230 Vac input are often relatively better, and theoretically, a higher power can be output. For the PFC + Flyback scheme, the operating efficiency of the PFC stage is also higher under high - voltage input than under low - voltage input. Therefore, the overall efficiency advantage under high - voltage input is more obvious, and the corresponding overall temperature rise will also be significantly reduced. This also means that under the same temperature rise requirement, the power transmission ability is stronger under high - voltage input.

[0004] Thus, it can be seen that the overall operating efficiency of the power adapter varies under different AC voltage inputs, which directly affects the transmission loss and overall temperature rise during the operation of the power supply.

[0005] Therefore, how to provide a power control device and a power control method to maximize the released output power has become one of the urgent problems to be solved in the industry. Summary of the Invention

[0006] The purpose of the present invention is to provide a power control device and a power control method, which can effectively solve at least one defect of the prior art.

[0007] To achieve the above object, the present invention provides a power control device, which includes: a power conversion unit having a primary circuit and a secondary circuit connected through a transformer, the power conversion unit being configured to convert an AC input voltage of an AC power supply and output it to a load; and a control unit configured to control the actual output power output to the load not to exceed a maximum power limit according to a temperature signal and an input voltage signal, the maximum power limit being the smaller value of a first maximum power value related to the temperature signal and a second maximum power value related to the input voltage signal.

[0008] In some embodiments of the present invention, the control unit is configured to: when the input voltage signal is a low-voltage input, use a first voltage allowable power as the second maximum power value; when the input voltage signal is a high-voltage input, use a second voltage allowable power as the second maximum power value; wherein, the second voltage allowable power is greater than the first voltage allowable power.

[0009] In some embodiments of the present invention, the power control device is a power adapter, the first voltage allowable power is equal to the rated power of the power adapter, and the second voltage allowable power is greater than the rated power of the power adapter.

[0010] In some embodiments of the present invention, the input voltage signal is obtained from a detection node located between the AC power supply and the primary circuit through a voltage detection unit.

[0011] In some embodiments of the present invention, the power control device further includes a rectification circuit, the input end of the rectification circuit is electrically connected to the output end of the AC power supply, and the output end of the rectification circuit is electrically connected to the primary circuit, wherein the detection node is located at the output end of the AC power supply or at the output end of the rectification circuit.

[0012] In some embodiments of the present invention, the power control device further includes a power factor correction circuit, the power factor correction circuit is electrically connected between the output end of the rectification circuit and the primary circuit, wherein the input voltage signal is obtained from the output end of the rectification circuit before the power factor correction circuit is started.

[0013] In some embodiments of the present invention, the control unit is configured to: when the temperature signal is lower than a first threshold, use a first temperature-permitted power as the first maximum power value; when the temperature signal is greater than a second threshold, the control unit controls the power control device to perform over-temperature protection; when the temperature signal is between the first threshold and the second threshold, use a second temperature-permitted power as the first maximum power value; wherein, the first threshold is less than the second threshold, and the first temperature-permitted power is greater than the second temperature-permitted power.

[0014] In some embodiments of the present invention, the power control device is a power adapter, the first threshold is 80 °C, the first temperature-permitted power is 120% of the rated power of the power adapter, the second threshold is 100 °C, and the second temperature-permitted power is the rated power of the power adapter.

[0015] In some embodiments of the present invention, the temperature signal is obtained by collecting the temperature of the power control device itself, or by collecting the temperature of the secondary circuit.

[0016] In some embodiments of the present invention, the voltage detection unit is further configured to process the input voltage signal so that the processed input voltage signal can be recognized by the control unit as a low-voltage input or a high-voltage input.

[0017] In some embodiments of the present invention, the voltage detection unit includes:

[0018] A plurality of voltage-dividing resistors, the plurality of voltage-dividing resistors at least including a first voltage-dividing resistor and a second voltage-dividing resistor, the first voltage-dividing resistor and the second voltage-dividing resistor are sequentially connected in series between the detection node and a ground terminal;

[0019] A filter capacitor, connected in parallel with the second voltage-dividing resistor;

[0020] A voltage comparator, having a non-inverting input terminal, an inverting input terminal, a power supply terminal, and a comparison output terminal, the inverting input terminal is connected to the connection point between the first voltage-dividing resistor and the second voltage-dividing resistor, the non-inverting input terminal is connected to a reference voltage, and the power supply terminal is connected to a DC power supply; and

[0021] A switching element, having a switching input terminal and a switching output terminal, the switching input terminal is connected to the comparison output terminal of the voltage comparator;

[0022] The power control device further includes a signal isolation unit having a first input end and a first output end. The first input end of the signal isolation unit is connected to the switch output end of the switch element, and the first output end of the signal isolation unit is connected to the control unit;

[0023] When the input voltage signal is a high-voltage input, the comparison output end of the voltage comparator outputs a low level, the switch element is turned off, and the first output end of the signal isolation unit outputs a high level;

[0024] When the input voltage signal is a low-voltage input, the comparison output end of the voltage comparator outputs a high level, the switch element is turned on, and the first output end of the signal isolation unit outputs a low level.

[0025] In some embodiments of the present invention, the voltage detection unit includes:

[0026] A plurality of voltage-dividing resistors and a filter capacitor. The plurality of voltage-dividing resistors at least include a first voltage-dividing resistor and a second voltage-dividing resistor. The first voltage-dividing resistor and the second voltage-dividing resistor are sequentially connected in series between the detection node and a ground terminal, and the filter capacitor is connected in parallel with the second voltage-dividing resistor;

[0027] A three-terminal voltage regulator and a switch element. The three-terminal voltage regulator has a cathode, an anode, and a reference electrode. The switch element has a driving end, a switch input end, and a switch output end; and

[0028] A cathode resistor, a current-limiting resistor, a driving resistor, and a zener diode. The cathode resistor is electrically connected between a DC power supply and the cathode of the three-terminal voltage regulator. The driving resistor and the zener diode are connected in series between the cathode of the three-terminal voltage regulator and the driving end of the switch element. The current-limiting resistor is electrically connected between the DC power supply and the switch input end of the switch element;

[0029] The power control device further includes a signal isolation unit having a first input end and a first output end. The first input end of the signal isolation unit is connected to the switch output end of the switch element, and the first output end of the signal isolation unit is connected to the control unit;

[0030] When the input voltage signal is a high-voltage input, the cathode of the three-terminal voltage regulator outputs a low level, the switch element is turned off, and the first output end of the signal isolation unit outputs a high level;

[0031] When the input voltage signal is a low-voltage input, the cathode of the three-terminal voltage regulator outputs a high level, the switching element is turned on, and the first output terminal of the signal isolation unit outputs a low level.

[0032] In some embodiments of the present invention, the signal isolation unit is an optocoupler or a transformer.

[0033] In some embodiments of the present invention, the power control device further includes: a secondary current detection unit, connected between the secondary circuit and the load and connected to the control unit; the control unit is also communicatively connected to the load through a communication line; wherein, when the input voltage signal is the low-voltage input, the control unit announces that the power control device has a first current drawing capacity and limits the overcurrent protection current threshold of the secondary circuit to a first current value; wherein, when the input voltage signal is the high-voltage input, the control unit announces that the power control device has a second current drawing capacity and limits the overcurrent protection current threshold of the secondary circuit to a second current value; wherein, the current value corresponding to the first current drawing capacity is less than the current value corresponding to the second current drawing capacity, and the first current value is less than the second current value.

[0034] In some embodiments of the present invention, the voltage range of the low-voltage input is 100Vac to 127Vac, and the voltage range of the high-voltage input is 200Vac to 240Vac.

[0035] In some embodiments of the present invention, the power control device further includes: a signal isolation unit, connected between the voltage detection unit and the control unit and electrically isolating the input voltage signal, wherein the control unit is electrically connected to the secondary circuit.

[0036] To achieve the above object, the present invention also provides a power control method, which includes:

[0037] Configuring the power control device as described above;

[0038] Controlling, by the control unit of the power control device, the actual output power output to the load not to exceed a maximum power limit according to a temperature signal and an input voltage signal, where the maximum power limit is the smaller value of a first maximum power value related to the temperature signal and a second maximum power value related to the input voltage signal.

[0039] The present invention utilizes the characteristic that there are differences in the power transmission efficiency under high and low voltage AC inputs, enabling a power control device (such as a power adapter, etc.) to maximize the output power according to different input voltages and in combination with the actually detected temperature. For example, when the input voltage is low, the power adapter can operate at the maximum first output power P1 (i.e., the first voltage allowable power) for a long time; when the input voltage is high, the power adapter can operate at the maximum second output power P2 (i.e., the second voltage allowable power) (P2 > P1) for a long time.

[0040] In addition, with the wide application of, for example, a USB PD control chip (integrated with an MCU), if supplemented with a primary side input voltage detection circuit and a temperature detection circuit, the power adapter of the present invention can also give the currently allowable maximum rated output power according to the actual mains input voltage level, and actively guide the load (such as a PC, mobile phone, etc.) to draw power.

[0041] Additional aspects and advantages of the present invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] By describing its exemplary embodiments in detail with reference to the accompanying drawings, the above and other features and advantages of the present invention will become more apparent.

[0043] Figure 1 is a block diagram of the working principle of the power control device of the present invention;

[0044] Figure 2 is a control logic block diagram of the power control device of the present invention;

[0045] Figure 3A shows Figure 1 a preferred embodiment of the voltage detection unit 50 in

[0046] Figure 3B shows Figure 1 another preferred embodiment of the voltage detection unit 50 in

[0047] Figure 4 is a flowchart of the power control method of the present invention.

[0048] Figure 5 is a preferred embodiment of the power control device of the present invention; DETAILED DESCRIPTION OF THE EMBODIMENTS

[0049] Example embodiments will now be described more fully with reference to the accompanying drawings. However, the example embodiments can be implemented in various forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the concept of the example embodiments to those skilled in the art. Like reference numerals in the figures denote like or similar structures and thus their detailed description will be omitted.

[0050] When introducing the elements / components / etc. described and / or illustrated herein, the terms "a", "an", "the", "said", and "at least one" are used to indicate the presence of one or more elements / components / etc. The terms "comprising", "including", and "having" are used to mean an open inclusion and mean that there may be additional elements / components / etc. in addition to the listed elements / components / etc. The term "connected" is used to indicate a direct connection between two elements / components, or an indirect connection (i.e., there are other elements / components between the two elements / components, such as including but not limited to air, etc.). In addition, the terms "first", "second", etc. in the claims are only used as labels and are not numerical limitations on their objects.

[0051] As Figure 1 shown, a working principle block diagram of the power control device 100 of the present invention is shown. The power control device 100 of the present invention mainly includes a power conversion unit 10 and a control unit 20. The power conversion unit 10 has a primary circuit 11 and a secondary circuit 12 connected through a transformer T. The power conversion unit 10 can be configured to convert an AC input voltage of an AC power supply 30 and output it to a load 40. The control unit 20 can be configured to control the actual output power output to the load 40 not to exceed a maximum power limit according to a temperature signal B and an input voltage signal A, and the maximum power limit is the smaller value of a first maximum power value related to the temperature signal B and a second maximum power value related to the input voltage signal A.

[0052] In some embodiments of the present invention, the power control device 100 can be, for example, a power adapter, and more preferably, for example, a power adapter compliant with the USB PD (USB Power Delivery) standard. However, the present invention is not limited thereto, and the power control device 100 of the present invention can also be extended to other power applications, such as an on-board charger (OBC).

[0053] As Figure 2 shown, it shows the specific control logic of the power control device 100 of the present invention. Among them, the input voltage signal can be processed and sent to the control unit (for example Figure 1The control unit 20) therein, and the input voltage signal sent to the control unit is marked as A for example. The temperature signal can be processed and sent to the control unit, and the temperature signal sent to the control unit is marked as B for example. In actual control, the input voltage signal A and the temperature signal B are in an "AND" relationship. If the second maximum power value related to the input voltage signal A is Pmax_A, and the first maximum power value related to the temperature signal B is Pmax_B, then the maximum power limit obtained according to the present invention is min(Pmax_A, Pmax_B), that is, the smaller value of Pmax_A and Pmax_B. The control unit of the present invention can finally control the actual output power output to the load not to exceed the maximum power limit min(Pmax_A, Pmax_B).

[0054] Continuing to refer to Figure 1 , in some embodiments of the present invention, the power control device 100 preferably further includes a rectifier circuit 60, whose input end can be electrically connected to the output end of the AC power supply 30, and whose output end can be electrically connected to the primary circuit 11. In the present invention, the input voltage signal A can be obtained, for example, by the voltage detection unit 50 from a detection node located between the AC power supply 30 and the primary circuit 11. In Figure 1 the illustrated embodiment, the detection node can be located at the output end of the AC power supply 30 (such as node N1), or at the output end of the rectifier circuit 60 (such as node N2), but the present invention is not limited thereto.

[0055] In some embodiments of the present invention, for the case where the detection signal is on the primary side of the transformer T, electrical isolation can be further performed using a signal isolation device. In other words, the power control device 100 of the present invention can further include a signal isolation unit 70, which can be connected between the voltage detection unit 50 and the control unit 20 and electrically isolate the input voltage signal, wherein the control unit 20 is electrically connected to the secondary circuit 12. Preferably, the signal isolation unit 70 can be, for example, an optocoupler (such as Figure 3A or Figure 3B shown as "OC" in

[0056] Take Figure 1Taking the illustrated embodiment as an example, the voltage detection unit 50 can obtain the input voltage signal V1 from the node N1, or obtain the input voltage signal V2 from the node N2. These input voltage signals V1 or V2 are processed and then sent to the control unit 20. In the present invention, the so-called "processing" includes but is not limited to, for example, processing the input voltage signal V1 or V2 into a signal that can be recognized by the control unit 20 (such as a secondary side PD control chip) and / or further processed subsequently, and / or, for example, electrically isolating the input voltage signal V1 or V2, etc.

[0057] In some embodiments of the present invention, the temperature signal B can be obtained by collecting the temperature of the power control device 100 itself, specifically by collecting the temperature of the components in the power control device 100 that reflect the overall machine temperature, or can also be obtained by collecting the temperature of the secondary side circuit 12, and these are not limitations to the present invention. In addition, the method of collecting temperature includes but is not limited to using a temperature sensor and other methods for collection.

[0058] In some embodiments of the present invention, the power control device 100 may further include a power factor correction circuit 90 (as Figure 5 shown). The power factor correction circuit 90 can be electrically connected, for example, between the output terminal of the rectification circuit 60 and the primary side circuit 11. In these embodiments, the voltage detection unit 50 can also obtain the input voltage signal V3 through the output terminal (node N3) of the power factor correction circuit 90, and at this time, the input voltage signal V3 needs to be obtained before the power factor correction circuit 90 is started. The reason for obtaining the input voltage signal before the power factor correction circuit 90 is started is that the power factor correction circuit 90 will adjust the input voltage signal after it is started, and the relative magnitude of the input voltage signal cannot be correctly reflected.

[0059] In some embodiments of the present invention, the control unit 20 can be configured to: when the input voltage signal A is a low-voltage input, use a first voltage-allowed power as the second maximum power value; when the input voltage signal A is a high-voltage input, use a second voltage-allowed power as the second maximum power value; wherein, the second voltage-allowed power is greater than the first voltage-allowed power. Preferably, the voltage range of the low-voltage input can be, for example, 100Vac - 127Vac, and the voltage range of the high-voltage input can be, for example, 200Vac - 240Vac, but the present invention is not limited thereto.

[0060] Taking the power control device 100 as a power adapter with a rated power of 100W as an example, the first voltage allowable power is, for example, equal to the rated power of the power adapter (i.e., "the first voltage allowable power = 100W"), and the second voltage allowable power is, for example, greater than the rated power of the power adapter (i.e., "the second voltage allowable power > 100W", for example, it can be 130W, but the present invention is not limited thereto). Thus, when the input voltage signal A is a low-voltage input, the first voltage allowable power can be used as the second maximum power value (i.e., Pmax_A = 100W); when the input voltage signal A is a high-voltage input, the second voltage allowable power can be used as the second maximum power value (i.e., Pmax_A = 130W).

[0061] Correspondingly, in these embodiments, the voltage detection unit 50 can also be configured to process the input voltage signal (such as Figure 1 the input voltage signal V1 or V2 therein) so that the processed input voltage signal A can be recognized as a low-voltage input or a high-voltage input by the control unit 20.

[0062] In some embodiments of the present invention, the control unit 20 can also be configured to: when the temperature signal B is lower than a first threshold, use a first temperature allowable power as the first maximum power value; when the temperature signal B is greater than a second threshold, the control unit controls the power control device to perform over-temperature protection; when the temperature signal B is between the first threshold and the second threshold, use a second temperature allowable power as the first maximum power value; wherein, the first threshold is less than the second threshold, and the first temperature allowable power is greater than the second temperature allowable power.

[0063] Similarly, taking the power control device 100 as a power adapter with a rated power of 100W as an example, the first threshold can be, for example, 80°C, the first temperature allowable power can be, for example, 120% of the rated power of the power adapter (i.e., "the first temperature allowable power = 120W"), the second threshold is, for example, 100°C, and the second temperature allowable power is, for example, the rated power of the power adapter (i.e., "the second temperature allowable power = 100W"). Thus, when the temperature signal B is lower than 80°C (i.e., the first threshold), the first temperature allowable power can be used as the first maximum power value (i.e., Pmax_B = 120W); when the temperature signal B is greater than 100°C (i.e., the second threshold), the control unit 20 controls the power control device 100 to perform over-temperature protection (OTP); when the temperature signal B is between 80 and 100°C, the second temperature allowable power is used as the first maximum power value (i.e., Pmax_B = 100W).

[0064] As Figure 3A shown, it shows Figure 1A preferred embodiment of the voltage detection unit 50 in. In this embodiment, the voltage detection unit 50 preferably may include a plurality of voltage dividing resistors (such as R1, R2, R11 in the figure), a filtering capacitor C1, a three-terminal voltage regulator VC (such as TL431), a switching element G, a cathode resistor R3, a current limiting resistor R5, a driving resistor R4, and a zener diode D. Among them, the plurality of voltage dividing resistors may at least include a first voltage dividing resistor R1 and a second voltage dividing resistor R2, and the first voltage dividing resistor R1 and the second voltage dividing resistor R2 are sequentially connected in series between a detection node (such as Figure 1 the node N1 in). The filtering capacitor C1 is connected in parallel with the second voltage dividing resistor R2. The three-terminal voltage regulator VC has a cathode VC1, a reference electrode VC2, and an anode VC3. The switching element G has a driving end G1, a switching input end G2, and a switching output end G3. The cathode resistor R3 is electrically connected between the DC power supply VCC and the cathode VC1 of the three-terminal voltage regulator VC. The driving resistor R4 and the zener diode D are connected in series between the cathode VC1 of the three-terminal voltage regulator VC and the driving end G1 of the switching element G. The current limiting resistor R5 is electrically connected between the DC power supply VCC and the switching input end G2 of the switching element G. Among them, the zener diode D is used to match the voltage at VC1 when the three-terminal voltage regulator VC outputs a high level, so that the switching element G is in the conducting state; when the three-terminal voltage regulator VC outputs a low level, it matches the voltage at VC1, so that the switching element G is in the off state.

[0065] In Figure 3A the shown embodiment, the connection relationship between the voltage detection unit 50 and the signal isolation unit 70 is also shown. In Figure 3A it, the signal isolation unit 70 is, for example, an optocoupler OC, which has a first input terminal OC1 and a first output terminal OC2. Among them, the first input terminal OC1 is connected to the switching output terminal G3 of the switching element G, and the first output terminal OC2 is connected to the control unit (that is, such as Figure 1 the control unit 20 in). Among them, when the input voltage signal A of the power control device 100 of the present invention is a high-voltage input (at this time, the AC output of the AC power supply is a high-voltage output), the cathode VC1 of the three-terminal voltage regulator VC outputs a low level, the switching element G is turned off, and the first output terminal OC2 of the signal isolation unit 70 (such as the optocoupler OC) outputs a high level. When the input voltage signal A of the power control device 100 of the present invention is a low-voltage input (at this time, the AC output of the AC power supply is a low-voltage output), the cathode VC1 of the three-terminal voltage regulator VC outputs a high level, the switching element G is turned on, and the first output terminal OC2 of the signal isolation unit 70 (such as the optocoupler OC) outputs a low level. The control unit 20 identifies whether the input voltage signal is a high-voltage input or a low-voltage input according to the high / low level output from the first output terminal OC2 of the signal isolation unit 70.

[0066] In some other embodiments of the present invention, the plurality of voltage dividing resistors may further include, for example, a third voltage dividing resistor R11, or may further include a larger number of voltage dividing resistors, which are not limitations to the present invention. The signal isolation unit 70 (such as an optocoupler OC) may further have a terminal OC3 connected to a ground terminal PGND (such as the primary side reference ground), and a capacitor C2 is connected in parallel between the first output terminal OC2 and another terminal OC4, and the other terminal OC4 is connected to a ground terminal SGND (such as the secondary side reference ground), which are also not limitations to the present invention.

[0067] As Figure 3B shown, it shows Figure 1 another preferred embodiment of the voltage detection unit 50 in Figure 1 . In this embodiment, the voltage detection unit 50 preferably may include a plurality of voltage dividing resistors (such as R1 and R2 in the figure), a filtering capacitor C1, a voltage comparator U, and a switching element K1. Among them, the plurality of voltage dividing resistors may at least include a first voltage dividing resistor R1 and a second voltage dividing resistor R2, and the first voltage dividing resistor R1 and the second voltage dividing resistor R2 are sequentially connected in series between a detection node (such as OUT the node N1 in REF ) and a ground terminal PGND (such as the primary side reference ground). The filtering capacitor C1 is connected in parallel with the second voltage dividing resistor R2. The voltage comparator U may have a non-inverting input terminal (i.e., the “+” terminal), an inverting input terminal (i.e., the “-” terminal), a power supply terminal, and a comparison output terminal V CC , the inverting input terminal (i.e., the “-” terminal) is connected to the connection point N3 between the first voltage dividing resistor R1 and the second voltage dividing resistor R2, the non-inverting input terminal (i.e., the “+” terminal) is connected to a reference voltage V OUT , the power supply terminal specifically includes a positive power supply terminal and a negative power supply terminal, wherein the positive power supply terminal is connected to a DC power supply V OUT , the negative power supply terminal is connected to the secondary side ground terminal. The switching element K1 has a switching input terminal K1 and a switching output terminal K2, the switching input terminal K1 is connected to the comparison output terminal V OUTThe output is at a high level, the switching element K1 is turned on, and the first output terminal OC2 of the signal isolation unit (e.g., an optocoupler OC) outputs a low level. The control unit 20 identifies whether the input voltage signal is a high-voltage input or a low-voltage input based on the high / low level output from the first output terminal OC2 of the signal isolation unit 70.

[0068] In Figure 3B the illustrated embodiment, some connection relationships between the control unit 20 and the load 40 are also shown. In Figure 3B it, the control unit 20 (e.g., a PD control chip) is also connected to a thermistor R NTC for example. The thermistor R NTC is connected to a ground terminal SGND (e.g., the secondary side reference ground). Among them, the temperature signal B is obtained through the thermistor R NTC for example. The control unit 20 can also be communicatively connected to the cc port of the load 40 through a communication line CC. The GND port of the load 40 is connected to a ground terminal SGND (e.g., the secondary side reference ground) through a detection resistor Rs for example. The currents I S- and I S+ across the detection resistor Rs are fed into the control unit 20. The V BUS port of the load 40 is connected to the input voltage V in through a controllable switch K2 for example. The controllable switch K2 is controlled to be turned on / off by the control signal output from the GATE port of the control unit 20. A capacitor C3 is also connected between the input voltage V in and the ground terminal SGND.

[0069] Continue to refer to Figure 1, in some embodiments of the present invention, the power control device 100 may further include a secondary current detection unit 80 for detecting the secondary current I1, which is connected between the secondary circuit 12 and the load 40 and is connected to the control unit 50. The control unit 20 and the load 40 are communicatively connected via a communication line CC. Wherein, when the input voltage signal A is a low-voltage input, the control unit 20 may announce to the load 40 via the communication line CC that the power control device 100 has a first current drawing capacity and limit the over-current protection current threshold of the secondary circuit 12 to a first current value; when the input voltage signal A is a high-voltage input, the control unit 200 may announce to the load 40 via the communication line CC that the power control device 100 has a second current drawing capacity and limit the over-current protection current threshold of the secondary circuit 12 to a second current value. Taking the power control device 100 as a power adapter with a rated power of 100W as an example, when the input voltage signal A is a low-voltage input of 100Vac, the control unit 20 may announce to the load 40 via the communication line CC that the power control device 100 has a current drawing capacity of 5A (i.e., the first current drawing capacity), the rated power allowed to continuously operate is 100W, and limit the over-current protection current threshold (i.e., OCP) of the secondary circuit 12 to 6.5A (i.e., the first current value). When the input voltage signal A is a high-voltage input of 230Vac, the control unit 20 announces that the power control device 100 has a current drawing capacity of 6.5A (i.e., the second current drawing capacity), the rated power allowed to continuously operate can be switched to 130W, increasing the power output capacity by 30W, and limit the over-current protection current threshold (i.e., OCP) of the secondary circuit 12 to 7.5A (i.e., the second current value). Wherein, the current value corresponding to the first current drawing capacity (e.g., 5A) is less than the current value corresponding to the second current drawing capacity (e.g., 6.5A), and the first current value (e.g., 6.5A) is less than the second current value (e.g., 7.5A).

[0070] As Figure 4 shown, it shows the flow of a power control method 400 of the present invention. The power control method 400 mainly includes:

[0071] S401: Configure a power control device (including but not limited to the power control device 100 described above);

[0072] S402: Control, by the control unit of the power control device, the actual output power output to the load not to exceed a maximum power limit according to a temperature signal and an input voltage signal, where the maximum power limit is the smaller value of a first maximum power value related to the temperature signal and a second maximum power value related to the input voltage signal.

[0073] It can be seen that the present invention utilizes the characteristic that there are differences in the power transmission efficiency under high and low voltage AC inputs, enabling a power control device (such as a power adapter, etc.) to maximize the output power according to different input voltages in combination with the actually detected temperature. For example, when the input voltage is low, the power adapter can operate at a maximum first output power P1 (i.e., the first voltage allowable power) for a long time; when the input voltage is high, the power adapter can operate at a maximum second output power P2 (i.e., the second voltage allowable power) (P2 > P1) for a long time.

[0074] In addition, the present invention can use the control unit 20, such as a USB PD control chip (integrated with an MCU), supplemented by a primary input voltage detection circuit and a temperature detection circuit. With the power adapter of the present invention, it can also give the currently allowable maximum rated output power according to the actual mains input voltage level, and actively guide the load (such as a PC, mobile phone, etc.) to draw load.

[0075] Taking a power adapter with a rated output of 20Vac / 5A as an example, the rated power on its safety label corresponds to 100W, and it is applicable to mains voltage inputs worldwide. However, in reality, there may also be cases where customers only require compliance with the CCC standard, that is, it is only sold in the Chinese mainland. This means that the product will only be used under a 220Vac input. When the input voltage is 220Vac, the overall machine temperature rise is small, and it can actually continuously operate at a power of 120W or even higher. By using a USB PD control chip (integrated with an MCU) and supplemented by a primary input voltage detection circuit and a temperature detection circuit, this power adapter can give the currently allowable maximum rated output power according to the actual mains input voltage level, thereby guiding the load (PC, mobile phone, etc.) to draw load.

[0076] In summary, the present invention can adaptively give different rated output power limits according to different mains inputs and actual operating temperatures, determine the current power transmission capacity of the power supply, actively guide the current draw of the system end, and maximize the output power.

[0077] The above specifically shows and describes the exemplary embodiments of the present invention. It should be understood that the present invention is not limited to the disclosed embodiments. On the contrary, the present invention is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.

Claims

1. A power control device, characterized in that, Comprising: A power conversion unit having a primary circuit and a secondary circuit connected by a transformer, the power conversion unit being configured to convert an AC input voltage of an AC power supply and output it to a load; A control unit configured to control the actual output power output to the load not to exceed a maximum power limit according to a temperature signal and an input voltage signal, the maximum power limit being the smaller of a first maximum power value related to the temperature signal and a second maximum power value related to the input voltage signal.

2. The power control device according to claim 1, characterized in that, The control unit is configured to: When the input voltage signal is a low-voltage input, use a first voltage allowable power as the second maximum power value; When the input voltage signal is a high-voltage input, use a second voltage allowable power as the second maximum power value; Wherein, the second voltage allowable power is greater than the first voltage allowable power.

3. The power control device according to claim 2, characterized in that, The power control device is a power adapter, the first voltage allowable power is equal to the rated power of the power adapter, and the second voltage allowable power is greater than the rated power of the power adapter.

4. The power control device according to claim 1, wherein The input voltage signal is obtained by a voltage detection unit from a detection node located between the AC power supply and the primary circuit.

5. The power control device according to claim 4, characterized in that, The power control device further includes a rectifier circuit, the input end of the rectifier circuit is electrically connected to the output end of the AC power supply, and the output end of the rectifier circuit is electrically connected to the primary circuit, wherein the detection node is located at the output end of the AC power supply or at the output end of the rectifier circuit.

6. The power control device according to claim 5, wherein The power control device further includes a power factor correction circuit, the power factor correction circuit is electrically connected between the output end of the rectifier circuit and the primary circuit, wherein the input voltage signal is obtained from the output end of the rectifier circuit before the power factor correction circuit is started.

7. The power control device according to claim 1, characterized in that, The control unit is configured to: When the temperature signal is lower than a first threshold, use a first temperature allowable power as the first maximum power value; When the temperature signal is greater than a second threshold, the control unit controls the power control device to perform over-temperature protection; When the temperature signal is between the first threshold and the second threshold, use a second temperature allowable power as the first maximum power value; Wherein, the first threshold is less than the second threshold, and the first temperature allowable power is greater than the second temperature allowable power.

8. The power control device according to claim 7, characterized in that, The power control device is a power adapter, the first threshold is 80 °C, the first temperature allowable power is 120% of the rated power of the power adapter, the second threshold is 100 °C, and the second temperature allowable power is the rated power of the power adapter.

9. The power control device according to claim 1, characterized in that, The temperature signal is obtained by collecting the temperature of the power control device itself, or by collecting the temperature of the secondary circuit.

10. The power control device according to claim 4, characterized in that, The voltage detection unit is further configured to process the input voltage signal so that the processed input voltage signal can be recognized as a low-voltage input or a high-voltage input by the control unit.

11. The power control device according to claim 10, wherein The voltage detection unit includes: A plurality of voltage dividing resistors, where the plurality of voltage dividing resistors at least includes a first voltage dividing resistor and a second voltage dividing resistor, and the first voltage dividing resistor and the second voltage dividing resistor are sequentially connected in series between the detection node and a ground terminal; A filtering capacitor, connected in parallel with the second voltage dividing resistor; A voltage comparator, having a non-inverting input terminal, an inverting input terminal, a power supply terminal, and a comparison output terminal, where the inverting input terminal is connected to the connection point between the first voltage dividing resistor and the second voltage dividing resistor, the non-inverting input terminal is connected to a reference voltage, and the power supply terminal is connected to a DC power supply; and A switching element, having a switching input terminal and a switching output terminal, where the switching input terminal is connected to the comparison output terminal of the voltage comparator; The power control device further includes a signal isolation unit, having a first input terminal and a first output terminal, where the first input terminal of the signal isolation unit is connected to the switching output terminal of the switching element, and the first output terminal of the signal isolation unit is connected to the control unit; When the input voltage signal is a high-voltage input, the comparison output terminal of the voltage comparator outputs a low level, the switching element is turned off, and the first output terminal of the signal isolation unit outputs a high level; When the input voltage signal is a low-voltage input, the comparison output terminal of the voltage comparator outputs a high level, the switching element is turned on, and the first output terminal of the signal isolation unit outputs a low level.

12. The power control device according to claim 10, characterized in that, The voltage detection unit includes: A plurality of voltage dividing resistors and a filtering capacitor, where the plurality of voltage dividing resistors at least includes a first voltage dividing resistor and a second voltage dividing resistor, the first voltage dividing resistor and the second voltage dividing resistor are sequentially connected in series between the detection node and a ground terminal, and the filtering capacitor is connected in parallel with the second voltage dividing resistor; A three-terminal voltage regulator and a switching element, where the three-terminal voltage regulator has a cathode, an anode, and a reference electrode, and the switching element has a driving terminal, a switching input terminal, and a switching output terminal; and A cathode resistor, a current limiting resistor, a driving resistor, and a zener diode, where the cathode resistor is electrically connected between a DC power supply and the cathode of the three-terminal voltage regulator, the driving resistor and the zener diode are connected in series between the cathode of the three-terminal voltage regulator and the driving terminal of the switching element, and the current limiting resistor is electrically connected between the DC power supply and the switching input terminal of the switching element; The power control device further includes a signal isolation unit, having a first input terminal and a first output terminal, where the first input terminal of the signal isolation unit is connected to the switching output terminal of the switching element, and the first output terminal of the signal isolation unit is connected to the control unit; When the input voltage signal is a high-voltage input, the cathode of the three-terminal voltage regulator outputs a low level, the switching element is turned off, and the first output terminal of the signal isolation unit outputs a high level; When the input voltage signal is a low-voltage input, the cathode of the three-terminal voltage regulator outputs a high level, the switching element is turned on, and the first output terminal of the signal isolation unit outputs a low level.

13. The power control device according to claim 11 or 12, characterized in that, The signal isolation unit is an optocoupler or a transformer.

14. The power control device according to claim 1, wherein It further includes: A secondary side current detection unit, connected between the secondary side circuit and the load and connected to the control unit; The control unit is also communicatively connected to the load through a communication line; Wherein, when the input voltage signal is the low-voltage input, the control unit declares that the power control device has a first current drawing capacity and limits the over-current protection current threshold of the secondary side circuit to a first current value; Wherein, when the input voltage signal is the high-voltage input, the control unit declares that the power control device has a second current drawing capacity and limits the over-current protection current threshold of the secondary side circuit to a second current value; Wherein, the current value corresponding to the first current drawing capacity is less than the current value corresponding to the second current drawing capacity, and the first current value is less than the second current value.

15. The power control device according to claim 2, wherein The voltage range of the low-voltage input is 100Vac to 127Vac, and the voltage range of the high-voltage input is 200Vac to 240Vac.

16. The power control device according to claim 4, characterized in that, It further includes: A signal isolation unit, connected between the voltage detection unit and the control unit and electrically isolating the input voltage signal, wherein the control unit is electrically connected to the secondary side circuit.

17. A power control method, characterized in that It includes: A power control device configured as described in any one of claims 1 to 16; The control unit of the power control device controls the actual output power output to the load not to exceed a maximum power limit according to a temperature signal and an input voltage signal, and the maximum power limit is the smaller value of a first maximum power value related to the temperature signal and a second maximum power value related to the input voltage signal.

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