Method for realizing charging / discharging processing of secondary battery by fuel cell system

Abstract

The present invention relates to an electronic device, comprising a fuel cell providing a fuel voltage, a first switch, a rechargeable battery providing a battery voltage, a second switch, a relay, a driving circuit, and a controller. The first switch supplies the fuel voltage to a first node according to a first control signal. The second switch is coupled to the first node, and according to a second control signal, charges the rechargeable battery using the fuel voltage. The relay supplies the voltage of the first node to a load according to a third control signal. The driving circuit generates the first control signal, the second control signal, and the third control signal according to a driving signal. The controller generates the driving signal according to the fuel voltage and the battery voltage.

Description

Method for realizing charge and discharge processing of secondary battery by fuel cell system Technical Field

[0001] The present invention relates to the technical field of power supply control, and in particular to an electronic device having a fuel cell and a rechargeable battery, and a protection method, a power calculation method, and a power supply method thereof. Background Art

[0002] With the rapid development of alternative energy, various new battery architectures are constantly being proposed, and fuel cells are once again gaining attention. In order to more effectively utilize fuel cells, it is necessary to optimize the fuel cell battery pack to accelerate the application of fuel cells in real life.

[0003] Summary of the Invention

[0004] This invention proposes an electronic device and its protection method, power calculation method, and power supply method. By utilizing a fuel cell in conjunction with a rechargeable battery, this device compensates for the fuel cell's insufficient current driving capability and improves the rechargeable battery's endurance. Furthermore, this protection method, power calculation method, and power supply method help ensure the proper operation of the fuel cell and rechargeable battery combination and provide users with reliable information about the rechargeable battery's power level, enhancing the user experience.

[0005] In view of this, the present invention provides an electronic device comprising a fuel cell, a first switch, a rechargeable battery, a second switch, a relay, a drive circuit, and a controller. The fuel cell provides a fuel voltage. The first switch supplies the fuel voltage to a first node in response to a first control signal. The rechargeable battery provides a battery voltage. The second switch is coupled to the first node, wherein the second switch charges the rechargeable battery using the fuel voltage in response to a second control signal. The relay supplies the voltage of the first node to a load in response to a third control signal. The drive circuit generates the first control signal, the second control signal, and the third control signal in response to a drive signal. The controller generates the drive signal in response to the fuel voltage and the battery voltage.

[0006] According to some embodiments of the present invention, when the controller determines that the fuel voltage is greater than the battery voltage and the battery voltage is greater than a first threshold voltage, the drive circuit turns on the first switch and the relay and turns off the second switch.

[0007] According to some embodiments of the present invention, when the controller determines that the fuel voltage is lower than the battery voltage, the drive circuit turns on the relay and turns off the first switch and the second switch, wherein the rechargeable battery supplies power to the load through the external diode of the second switch.

[0008] According to some embodiments of the present invention, when the controller determines that the fuel voltage is equal to the battery voltage, the drive circuit turns on the first switch and the relay and turns off the second switch. The rechargeable battery supplies power to the load via the diode attached to the second switch, and the fuel cell supplies power to the load via the first switch.

[0009] According to some embodiments of the present invention, when the controller determines that the fuel voltage exceeds a first threshold voltage, the driving circuit turns off the first switch.

[0010] According to some embodiments of the present invention, when the controller determines that the battery voltage exceeds a second threshold voltage, the driving circuit turns off the second switch.

[0011] According to some embodiments of the present invention, the electronic device further includes a first voltage detection circuit and a second voltage detection circuit. The first voltage detection circuit is configured to detect the fuel voltage and generate a first voltage detection signal. The second voltage detection circuit is configured to detect the battery voltage and generate a second voltage detection signal. The controller determines the fuel voltage and the battery voltage based on the first and second voltage detection signals.

[0012] According to some embodiments of the present invention, the electronic device further includes a first current detector coupled between the second switch and the rechargeable battery, for detecting a battery current of the rechargeable battery and generating a first current detection signal.

[0013] According to some embodiments of the present invention, when the controller determines that the fuel voltage is greater than the battery voltage and determines that the charging current of the rechargeable battery exceeds the maximum charging current based on the first current detection signal, the drive circuit turns on the first switch and the relay and periodically turns on the second switch.

[0014] According to some embodiments of the present invention, when it is determined that the fuel voltage is greater than the battery voltage and it is determined based on the first current detection signal that the charging current of the rechargeable battery does not exceed the maximum charging current, the driving circuit turns on the first switch, the second switch, and the relay.

[0015] According to some embodiments of the present invention, when the relay is not conducting, the controller calculates the power level of the rechargeable battery using an open circuit voltage method, wherein the controller further determines whether the battery current of the rechargeable battery exceeds a first current based on the first current detection signal.

[0016] In practical applications, the open circuit voltage method described in this technical solution will calculate the power of the rechargeable battery in the following way:

[0017] When the system voltage is 39-54V, the battery state of charge (SOC) efficiency is between 0% and 100%, that is, when the battery is fully charged, SOC = 100%, and when the battery is fully discharged, SOC = 0%. The battery state of charge (SOC) can be expressed by the following formula:

[0018] SOC = (battery voltage × battery voltage × A) - (B × battery voltage) + C

[0019] Among them, A=0.2934, B=20.438, C=347.82.

[0020] The battery voltage of 39 to 54 V corresponds to 0 to 100% of the battery capacity (SOC). The corresponding values ​​of the battery voltage and the battery capacity (SOC) are measured and a corresponding curve of the voltage and the battery capacity (SOC) is drawn.

[0021] The above quadratic equation is then used to approximate the actual voltage versus battery capacity (SOC) curve.

[0022] A, B, and C are the actual values ​​of the coefficients of the approximated quadratic equation in this case.

[0023] According to some embodiments of the present invention, when the battery current of the rechargeable battery exceeds the first current, the controller calculates the power of the rechargeable battery using the ampere-hour method, wherein when the battery current of the rechargeable battery does not exceed the first current, the controller calculates the power of the rechargeable battery again using the open circuit voltage method after a first predetermined time.

[0024] In practical applications, the ampere-hour method described in this technical solution will calculate the power of the rechargeable battery in the following manner:

[0025] The total battery capacity is 32Ah;

[0026] The battery charge and discharge current measured per second is I;

[0027] Calculate the increase or decrease in battery capacity per second (i.e. Q = I × △t) to calculate the current battery capacity;

[0028] SOC = current battery capacity / total battery capacity

[0029] That is, this technical solution combines the open circuit voltage method with the ampere-hour method to determine the SOC, thereby effectively eliminating the error caused by the inaccurate measurement of the battery charge and discharge current.

[0030] The present invention also provides a power supply method applicable to an electronic device. The electronic device includes a fuel cell, a first switch, a second switch, a rechargeable battery, and a relay, wherein the first switch is coupled between the fuel cell and a first node, the second switch is coupled between the first node and the rechargeable battery, and the relay is coupled between the first node and a load. The power supply method includes detecting a fuel voltage of one of the fuel cells; detecting a battery voltage of one of the rechargeable batteries; and controlling the first switch, the second switch, and the relay to conduct or not conduct based on the fuel voltage and the battery voltage.

[0031] According to some embodiments of the present invention, the step of controlling the first switch, the second switch and the relay to be turned on and off according to the fuel voltage and the battery voltage also includes turning on the first switch, the second switch and the relay when the fuel voltage is greater than the battery voltage and the battery voltage is not greater than a first threshold voltage.

[0032] According to some embodiments of the present invention, the step of controlling the conduction and non-conduction of the first switch, the second switch and the relay according to the fuel voltage and the battery voltage further includes turning on the first switch and the relay and turning off the second switch when the fuel voltage is greater than the battery voltage and the battery voltage is greater than a first threshold voltage.

[0033] According to some embodiments of the present invention, the step of controlling the first switch, the second switch, and the relay to be conductive or non-conductive based on the fuel voltage and the battery voltage further includes, when the fuel voltage is lower than the battery voltage, turning on the relay and turning off the first switch and the second switch. The rechargeable battery supplies power to the load via an external diode of the second switch.

[0034] According to some embodiments of the present invention, the step of controlling the first switch, the second switch, and the relay to be conductive and non-conductive based on the fuel voltage and the battery voltage further includes, when the fuel voltage is equal to the battery voltage, turning on the first switch and the relay and turning off the second switch. The rechargeable battery supplies power to the load via an external diode of the second switch, and the fuel cell supplies power to the load via the first switch.

[0035] According to some embodiments of the present invention, the power supply method further includes detecting a charging current of the rechargeable battery. The step of controlling the first switch, the second switch, and the relay to be conductive and non-conductive based on the fuel voltage and the battery voltage further includes, when the fuel voltage is greater than the battery voltage and the charging current exceeds a maximum charging current, turning on the first switch and the relay and periodically turning on the second switch.

[0036] According to some embodiments of the present invention, the step of controlling the first switch, the second switch and the relay to be turned on and off according to the fuel voltage and the battery voltage also includes turning on the first switch, the second switch and the relay when the fuel voltage is greater than the battery voltage and the charging current does not exceed the maximum charging current. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] FIG1 is a schematic diagram of an electronic device according to an embodiment of the present invention;

[0038] FIG2 is a schematic diagram illustrating the operation of a controller and a driving circuit of an electronic device according to an embodiment of the present invention;

[0039] FIG3 is a schematic diagram of an electronic device according to another embodiment of the present invention;

[0040] FIG4 is a schematic diagram of an electronic device operating in a first mode according to an embodiment of the present invention;

[0041] FIG5 is a schematic diagram of an electronic device operating in a second mode according to an embodiment of the present invention;

[0042] FIG6 is a schematic diagram of an electronic device operating in a third mode according to an embodiment of the present invention;

[0043] FIG7 is a schematic diagram of an electronic device operating in a fourth mode according to an embodiment of the present invention;

[0044] FIG8 is a circuit diagram of a voltage detection circuit according to an embodiment of the present invention;

[0045] FIG9 is a circuit diagram of a temperature detection circuit according to an embodiment of the present invention;

[0046] FIG10 is a flowchart of a protection method according to an embodiment of the present invention;

[0047] FIG11 is a flow chart of a method for calculating power according to an embodiment of the present invention; and

[0048] FIG12 is a flow chart of a power supply method according to an embodiment of the present invention.

[0049] Reference numerals

[0050] 100, 200, 300, 400, 500, 600, 700: electronic devices

[0051] 101: Fuel Cells

[0052] 102: One-way conduction component

[0053] 103: First switch

[0054] 104: First voltage detection circuit

[0055] 105: First temperature detection circuit

[0056] 106: Rechargeable battery

[0057] 107: Protection circuit

[0058] 108: Second switch

[0059] 109: First current detector

[0060] 110: Second voltage detection circuit

[0061] 111: Second temperature detection circuit

[0062] 112: Relay

[0063] 113: Second current detector

[0064] 114: Driving circuit

[0065] 115: Controller

[0066] 116: Peripheral power supply

[0067] 800: Voltage detection circuit

[0068] 900: Temperature detection circuit

[0069] 1000: Protection method

[0070] 1100: Power calculation method

[0071] 1200: Power supply method

[0072] VFC: fuel voltage

[0073] VBAT: battery voltage

[0074] N1: first node

[0075] N2: Second node

[0076] SW1: First control signal

[0077] SW2: Second control signal

[0078] SW3: The third control signal

[0079] VS1: First voltage detection signal

[0080] VS2: Second voltage detection signal

[0081] SC: driving signal

[0082] IS1: First current detection signal

[0083] IS2: Second current detection signal

[0084] TS1: First temperature detection signal

[0085] TS2: Second temperature detection signal

[0086] IBAT: battery current

[0087] IL: load current

[0088] LOAD: load

[0089] D1: diode

[0090] D2: external diode

[0091] NA: Anode end

[0092] NC: cathode terminal

[0093] RA: first resistor

[0094] RB: Second resistor

[0095] RC: third resistor

[0096] VX: voltage to be measured

[0097] VS: voltage detection signal

[0098] RT: Thermistor

[0099] C1: first capacitor

[0100] VDD: supply voltage

[0101] S1010~S1070, S1110~S1140, S1210~S1280: Step Flow DETAILED DESCRIPTION

[0102] The following description is of embodiments of the present invention. Its purpose is to illustrate the general principles of the present invention and should not be regarded as limiting the present invention. The scope of protection of the present invention shall be based on the scope of protection defined by the scope of the patent application.

[0103] It is understood that although the terms "first," "second," "third," etc. may be used herein to describe various components, constituents, regions, layers, and / or parts, these components, constituents, regions, layers, and / or parts should not be limited by these terms, and these terms are merely used to distinguish different components, constituents, regions, layers, and / or parts. Thus, a first component, component, region, layer, and / or part discussed below may be referred to as a second component, component, region, layer, and / or part without departing from the teachings of some embodiments disclosed herein.

[0104] It is noteworthy that the content disclosed below can provide multiple embodiments or examples for practicing the different features of the present invention. The special component examples and arrangements described below are only used to briefly explain the inventive spirit of the present invention and are not used to limit the scope of protection of the present invention. In addition, the following description may reuse the same component symbols or text in multiple examples. However, the purpose of repetition is only to provide a simplified and clear description and is not used to limit the relationship between the multiple embodiments and / or configurations discussed below. In addition, the description of a feature connected to, coupled to and / or formed on the upper level of another feature described in the following description may actually include multiple different embodiments, including direct contact between such features, or including other additional features formed between such features, etc., so that such features are not in direct contact.

[0105] FIG1 is a schematic diagram showing an electronic device according to an embodiment of the present invention. As shown in FIG1 , the electronic device 100 includes a fuel cell 101 , a unidirectional conducting element 102 , a first switch 103 , a first voltage detection circuit 104 , and a first temperature detection circuit 105 .

[0106] The fuel cell 101 provides a fuel voltage VFC, and the unidirectional conducting component 102 is used to unidirectionally provide the fuel voltage VFC to the first switch 103. According to one embodiment of the present invention, the unidirectional conducting component 102 is a diode. According to another embodiment of the present invention, the unidirectional conducting component 102 is a Schottky diode.

[0107] The first switch 103 is coupled between the fuel cell 101 and the first node N1 and is turned on and off according to the first control signal SW1. According to one embodiment of the present invention, the first switch 103 is a metal oxide semiconductor.

[0108] The first voltage detection circuit 104 is used to detect the fuel voltage VFC and generate a first voltage detection signal VS1. The first temperature detection circuit 105 is used to detect the temperature of the first switch 103 and generate a first temperature detection signal TS1.

[0109] As shown in FIG. 1 , the electronic device 100 further includes a rechargeable battery 106 , a second switch 108 , a first current detector 109 , a second voltage detection circuit 110 , and a second temperature detection circuit 111 .

[0110] The rechargeable battery 106 provides a battery voltage VBAT. According to some embodiments of the present invention, the rechargeable battery 106 may be a lead-acid battery, a nickel-metal hydride (Ni-MH) battery, a lithium-ion (Li-ion) battery, a lithium-ion polymer (Li-Po) battery, a high-voltage lithium-ion polymer battery (Li-HV), a lithium iron phosphate (Li-Fe) battery, or any other reusable battery.

[0111] According to one embodiment of the present invention, when the rechargeable battery 106 is a battery pack composed of a lithium-ion (Li-ion) battery, a lithium-ion polymer (Li-Po) battery, a high-voltage lithium-ion polymer (Li-HV) battery, or a lithium iron phosphate (Li-Fe) battery, the electronic device 100 may further include a protection circuit 107 to protect the voltage of each battery cell of the rechargeable battery 106 from exceeding a threshold voltage and to keep the voltages of each battery cell close to each other.

[0112] According to one embodiment of the present invention, when the rechargeable battery 106 is composed of a plurality of lithium-ion or lithium-ion polymer battery cells connected in series, the protection circuit 107 is configured to protect the voltage of each battery cell from exceeding 4.2V. According to another embodiment of the present invention, when the rechargeable battery 106 is composed of a plurality of high-voltage lithium-ion polymer (Li-HV) battery cells connected in series, the protection circuit 107 is configured to protect the voltage of each battery cell from exceeding 4.35V. According to another embodiment of the present invention, when the rechargeable battery 106 is composed of a plurality of lithium iron phosphate battery cells connected in series, the protection circuit 107 is configured to protect the voltage of each battery cell from exceeding 3.65V.

[0113] The second switch 108 is coupled between the first node N1 and the rechargeable battery 106 and charges the rechargeable battery 106 by converting the voltage at the first node N1 to the rechargeable battery 106 according to a second control signal SW2. According to one embodiment of the present invention, the second switch 108 is an insulated gate bipolar transistor (IGBT). According to one embodiment of the present invention, the rechargeable battery 106 is discharged to the load LOAD through an external diode (not shown in FIG. 1 ) connected to the second switch 108.

[0114] The first current detector 109 is coupled between the rechargeable battery 106 and the second switch 108 to measure the battery current IBAT and generate a first current detection signal IS1. According to some embodiments of the present invention, the battery current IBAT includes a charging current for charging the rechargeable battery 106 and a discharging current of the rechargeable battery 106.

[0115] The second voltage detection circuit 110 is used to detect the battery voltage VBAT of the rechargeable battery 106 and generate a second voltage detection signal VS2. The second temperature detection circuit 111 is used to detect the temperature of the rechargeable battery 106 and generate a second temperature detection signal TS2.

[0116] 1 , the electronic device 100 further includes a relay 112, a second current detector 113, a driving circuit 114, a controller 115, and a peripheral power supply 116. The relay 112 is coupled between the first node N1 and the load LOAD, and provides the voltage of the first node N1 to the load LOAD according to the third control signal SW3.

[0117] The second current detector 113 is coupled between the first node N1 and the relay 112 to measure the load current IL flowing through the load LOAD and generate a second current detection signal IS2. According to one embodiment of the present invention, the second current detector 113 is used to detect the total output current of the fuel cell 101 and the rechargeable battery 106. According to some embodiments of the present invention, the first current detector 109 and the second current detector 113 are Hall effect sensors.

[0118] The driver circuit 114 generates a first control signal SW1, a second control signal SW2, and a third control signal SW3 based on the driver signal SC, thereby controlling the first switch 103, the second switch 108, and the relay 112 to conduct and not conduct. The controller 115 generates the driver signal SC based on the first temperature detection signal TS1, the second temperature detection signal TS2, the first current detection signal IS1, the second current detection signal IS2, the first voltage detection signal VS1, and the second voltage detection signal VS2. The driver circuit 114 and the controller 115 are described in detail below.

[0119] The peripheral power supply 116 is coupled to the first node N1 and is used to power the electronic device 100. As shown in FIG1 , the relay 112 is coupled after the peripheral power supply 116, and the second current detector 113 detects the sum of the current flowing to the load LOAD and the current flowing to the peripheral power supply 116.

[0120] Figure 2 is a schematic diagram illustrating the operation of a controller and a driving circuit of an electronic device according to an embodiment of the present invention. As shown in Figure 2 , a peripheral power supply 116 provides power to the first temperature detection circuit 105 , the first current detector 109 , the second temperature detection circuit 111 , the second current detector 113 , the driving circuit 114 , and the controller 115 .

[0121] According to some embodiments of the present invention, the peripheral power supply 116 provides a supply voltage to the first temperature detection circuit 105 , the first current detector 109 , the second temperature detection circuit 111 , the second current detector 113 , the driving circuit 114 and the controller 115 .

[0122] According to other embodiments of the present invention, when the fuel cell 101 reacts to generate the fuel voltage VFC, auxiliary circuits (not shown in FIG. 1 and FIG. 2 ) are required to assist the fuel cell 101 in reacting efficiently. These auxiliary circuits are powered by the peripheral power supply 116 .

[0123] In addition, the controller 115 receives the first voltage detection signal VS1 generated by the first voltage detection circuit 104, the first temperature detection signal TS1 generated by the first temperature detection circuit 105, the first current detection signal IS1 generated by the first current detector 109, the second voltage detection signal VS2 generated by the second voltage detection circuit 110, the second temperature detection signal TS2 generated by the second temperature detection circuit 111, and the second current detection signal IS2 generated by the second current detector 113 to generate a driving signal SC. The driving circuit 114 drives the first switch 103, the second switch 108, and the relay 112 using the first control signal SW1, the second control signal SW2, and the third control signal SW3 according to the driving signal SC.

[0124] As shown in FIG1 , because the current driving capability of the fuel cell 101 is relatively insufficient, the electronic device 100 further includes a rechargeable battery 106 to supplement the lower current driving capability of the fuel cell 101. According to other embodiments of the present invention, when the rechargeable battery 106 is not a lithium-ion (Li-ion) battery, a lithium-ion polymer (Li-Po) battery, a high-voltage lithium-ion polymer (Li-HV) battery, or a lithium iron phosphate (Li-Fe) battery, the electronic device 100 may omit the protection circuit 107 to reduce costs.

[0125] FIG3 is a schematic diagram illustrating an electronic device according to another embodiment of the present invention. Comparing electronic device 300 in FIG3 with electronic device 100 in FIG1 , FIG3 shows that unidirectional conduction element 102 in FIG1 is replaced with diode D1, and second switch 108 further includes an external diode D2. According to some embodiments of the present invention, rechargeable battery 106 supplies power to load LOAD via the external diode D2 of second switch 108.

[0126] 3 , diode D1 includes an anode terminal NA and a cathode terminal NC, wherein anode terminal NA is coupled to fuel cell 101, and cathode terminal NC is coupled to first switch 103. According to another embodiment of the present invention, diode D1 may be a Schottky diode to further reduce power loss caused by the voltage across the diode.

[0127] FIG4 is a schematic diagram illustrating an electronic device operating in a first mode according to an embodiment of the present invention. As shown in FIG4 , when the controller 115 determines that the fuel voltage VFC of the electronic device 400 is greater than the battery voltage VBAT and the charging current of the rechargeable battery 106 exceeds the maximum charging current IP, the controller 115 generates a drive signal SC to operate in the first mode. The drive circuit 114, in response to the drive signal SC, turns on the first switch 103 and the relay 112, and periodically turns on the second switch 108, such that the average charging current of the rechargeable battery 106 reaches the maximum charging current IP.

[0128] According to an embodiment of the present invention, the controller 115 samples the battery current IBAT N times within the first time period T1 and averages the samples to generate an average current IAVE, where the average current IAVE is expressed as Formula 1:

[0129]

[0130] Among them, i k is the current sampled for the kth time, and i=1~N.

[0131] According to an embodiment of the present invention, when the average current IAVE is not greater than the maximum charging current IP, it means that the second switch 108 is continuously turned on to safely charge the rechargeable battery 106 . Therefore, the second switch 108 is continuously turned on to safely charge the rechargeable battery 106 .

[0132] According to another embodiment of the present invention, when the average current IAVE is greater than the maximum charging current IP, in order to prevent the charging current per unit time from exceeding the maximum charging current IP, the on-time ratio DON of the second switch 108 is as shown in Formula 2:

[0133]

[0134] In other words, when the average current IAVE is greater than the maximum charging current IP, the second switch 108 is only conductive for the on-time ratio DON (i.e., T1×DON) during the first time T1, and is non-conductive during the rest of the time (i.e., T1×(1-DON)), so that the average charging current of the rechargeable battery 106 does not exceed the maximum charging current IP.

[0135] FIG5 is a schematic diagram illustrating an electronic device operating in a second mode according to an embodiment of the present invention. As shown in FIG5 , when the controller 115 determines that the fuel voltage VFC of the electronic device 500 is greater than the battery voltage VBAT and that the battery voltage VBAT exceeds a threshold voltage, indicating that the rechargeable battery 106 has sufficient charge, the controller 115 generates a drive signal SC to operate in the second mode. In response to the drive signal SC, the drive circuit 114 turns on the first switch 103 and the relay 112 and turns off the second switch 108.

[0136] When the drive circuit 114 does not turn on the second switch 108, the fuel voltage VFC of the fuel cell 101 directly powers the load LOAD, and the rechargeable battery 106 can also power the load LOAD via the external diode D2 of the second switch 108. Since the second switch 108 is not conducting, the fuel cell 101 does not charge the rechargeable battery 106.

[0137] FIG6 is a schematic diagram illustrating an electronic device operating in a third mode according to an embodiment of the present invention. As shown in FIG6 , when controller 115 determines that fuel voltage VFC of electronic device 600 is less than battery voltage VBAT, controller 115 generates a drive signal SC to operate in the third mode. Drive circuit 114, in response to drive signal SC, turns on relay 112 and turns off first switch 103 and second switch 108. Consequently, battery voltage VBAT of rechargeable battery 106 flows through diode D2 of second switch 108 to supply power to load LOAD.

[0138] FIG7 is a schematic diagram illustrating an electronic device operating in a fourth mode according to an embodiment of the present invention. As shown in FIG7 , when controller 115 determines that fuel voltage VFC of electronic device 700 is equal to battery voltage VBAT, controller 115 generates a drive signal SC to indicate operation in the fourth mode. Drive circuit 114, in response to drive signal SC, turns on first switch 103 and relay 112 and turns off second switch 108.

[0139] Since the first switch 103 is turned on, the fuel voltage VFC of the fuel cell 101 supplies power to the load LOAD, and the battery voltage VBAT of the rechargeable battery 106 supplies power to the load LOAD through the external diode D2 of the second switch 108 .

[0140] FIG8 is a circuit diagram of a voltage detection circuit according to an embodiment of the present invention. As shown in FIG8 , the voltage detection circuit 800 includes a first resistor RA and a second resistor RB. The voltage detection circuit 800 divides the voltage to be measured VX by the first resistor RA and the second resistor RB to generate a voltage detection signal VS, and provides the voltage detection signal VS to the controller 115.

[0141] According to one embodiment of the present invention, the voltage detection circuit 800 corresponds to the first voltage detection circuit 104 in FIG. 1 , and is configured to detect the fuel voltage VFC of the fuel cell 101 and generate a first voltage detection signal VS1. According to another embodiment of the present invention, the voltage detection circuit 800 corresponds to the second voltage detection circuit 110 in FIG. 1 , and is configured to detect the battery voltage VBAT of the rechargeable battery 106 and generate a second voltage detection signal VS2.

[0142] Figure 9 is a circuit diagram of a temperature detection circuit according to one embodiment of the present invention. As shown in Figure 9, temperature detection circuit 900 includes a thermistor RT, a third resistor RC, and a first capacitor C1. The thermistor RT is coupled between a supply voltage VDD and a second node N2, the third resistor RC is coupled between the second node N2 and ground, and the capacitor is coupled between the second node N2 and ground. According to one embodiment of the present invention, the thermistor RT has a negative temperature coefficient. In other words, the resistance of the thermistor RT decreases as the temperature increases.

[0143] According to one embodiment of the present invention, the resistance of thermistor RT changes with temperature. Furthermore, the supply voltage VDD is divided by thermistor RT and the third resistor RC to generate a temperature detection signal TS at the second node N2. Therefore, the controller 115 can infer the ambient temperature based on the voltage of the temperature detection signal TS. According to one embodiment of the present invention, the supply voltage VDD is provided by the peripheral power supply 116 in FIG. According to one embodiment of the present invention, the first capacitor C1 is used to stabilize the voltage of the temperature detection signal TS.

[0144] According to one embodiment of the present invention, the temperature detection circuit 900 corresponds to the first temperature detection circuit 105 of FIG. 1 , and is configured to detect the temperature of the first switch 103 and generate the first temperature detection signal TS1. According to another embodiment of the present invention, the temperature detection circuit 900 corresponds to the second temperature detection circuit 111 of FIG. 1 , and is configured to detect the temperature of the rechargeable battery 106.

[0145] FIG10 is a flow chart of a protection method according to an embodiment of the present invention. The following description of the protection method 1000 in FIG10 will be combined with the electronic device 100 in FIG1 for detailed explanation.

[0146] First, the controller 115 determines whether the fuel voltage VFC exceeds a first threshold voltage based on the first voltage detection signal VS1 generated by the first voltage detection circuit 104 (step S1010). If the fuel voltage VFC exceeds the first threshold voltage, the controller 115 controls the drive circuit 114 using the drive signal SC to turn off the first switch 103 (step S1020).

[0147] According to one embodiment of the present invention, when the fuel voltage VFC exceeds the first threshold voltage, the excessively high fuel voltage VFC may burn the load LOAD and / or the rechargeable battery 106 . To protect the load LOAD and the rechargeable battery 106 , the fuel cell 101 must be disconnected using the first switch 103 .

[0148] Returning to step S1010, if the fuel voltage VFC is determined not to have exceeded the first threshold voltage, the controller 115 determines whether the battery voltage VBAT of the rechargeable battery 106 has exceeded the second threshold voltage based on the second voltage detection signal VS2 generated by the second voltage detection circuit 110 (step S1030). If the battery voltage VBAT has exceeded the second threshold voltage, the controller 115 controls the driver circuit 114 using the drive signal SC to turn off the second switch 108 (step S1040).

[0149] According to one embodiment of the present invention, when the battery voltage VBAT exceeds the second threshold voltage, it indicates that the rechargeable battery 106 is fully charged or nearly fully charged. To protect the rechargeable battery 106, the second switch 108 is turned off to prevent overcharging of the rechargeable battery 106. However, the rechargeable battery 106 can still supply power to the load LOAD via the external diode (D2 as shown in FIG. 3 ) of the second switch 108.

[0150] Returning to step S1030, when it is determined that the battery voltage VBAT has not exceeded the second threshold voltage, the controller 115 determines whether the temperature of the rechargeable battery 106 has exceeded the first temperature based on the second temperature detection signal TS2 generated by the second temperature detection circuit 111 (step S1050). If it is determined that the temperature of the rechargeable battery 106 has exceeded the first temperature, the controller 115 controls the driving circuit 114 using the driving signal SC to turn off the first switch 106, the second switch 108, and the relay 112 (step S1060).

[0151] If the temperature of the rechargeable battery 106 is determined not to have exceeded the first temperature, the controller 115 determines whether the temperature of the first switch 103 has exceeded the second temperature based on the first temperature detection signal TS1 generated by the first temperature detection circuit 105 (step S1070). If the temperature of the first switch 103 has exceeded the second temperature, the controller 115 controls the drive circuit 114 using the drive signal SC to turn off the first switch 106, the second switch 108, and the relay 112 (step S1060).

[0152] When it is determined that the temperature of the first switch 103 does not exceed the second temperature, the controller 115 ends the protection method 1000. According to some embodiments of the present invention, the controller 115 executes the protection method 1000 at predetermined intervals to ensure that the electronic device 100 operates normally.

[0153] According to one embodiment of the present invention, since high temperatures can shorten the lifespan of the rechargeable battery 106 and high temperatures often indicate malfunctioning of the rechargeable battery 106 , when the temperature of the rechargeable battery 106 exceeds a first temperature, power to the load LOAD is stopped to prevent any danger. According to one embodiment of the present invention, since the first switch 106 is a component of the electronic device 100 that operates for an extended period of time, the temperature of the first switch 106 must be continuously monitored to protect the first switch 106 from damage due to high temperatures.

[0154] FIG11 is a flow chart of a method for calculating power according to an embodiment of the present invention. The following description of the method 1100 for calculating power in FIG11 will be combined with the electronic device 100 in FIG1 for detailed description.

[0155] First, when the electronic device 100 is initialized and the relay 112 is non-conductive, the controller 115 determines the battery voltage VBAT of the rechargeable battery 106 according to the second voltage detection signal VS2 generated by the second voltage detection circuit 110, and calculates the state of charge of the rechargeable battery 106 using the open circuit voltage method based on the battery voltage VBAT (step S1110).

[0156] According to one embodiment of the present invention, the controller 115 stores a lookup table. When the controller 115 obtains the battery voltage VBAT while the relay 112 is not conducting, the controller 115 searches the lookup table for the battery voltage VBAT corresponding to the battery voltage VBAT and uses the searched battery voltage as the battery capacity of the rechargeable battery 106. Different types of rechargeable batteries 106 correspond to different lookup tables.

[0157] Next, the controller 115 determines whether the battery current IBAT exceeds the first current according to the first current detection signal IS1 generated by the first current detector 109 (step S1120 ). According to one embodiment of the present invention, the battery current IBAT represents the charging current and discharging current of the rechargeable battery 106 .

[0158] When the battery current IBAT does not exceed the first current and lasts for more than the first predetermined time (step S1130), the controller 115 calculates the state of charge of the rechargeable battery 106 using the open circuit voltage method again (step S1110). According to some embodiments of the present invention, the first predetermined time is 30 minutes.

[0159] When it is determined that the battery current IBAT exceeds the first current, the controller 115 calculates the charge using the ampere-hour method (step S1140). According to some embodiments of the present invention, the first current is 1 ampere. According to some embodiments of the present invention, the controller 115 obtains an initial value of the charge of the rechargeable battery 106 using the open circuit voltage method. When the battery current IBAT is sufficiently large (i.e., the charging current and / or discharging current of the rechargeable battery 106 exceeds the first current), the controller 115 calculates the charge of the rechargeable battery 106 after charging and / or discharging using the ampere-hour method based on the initial value of the charge obtained using the open circuit voltage method.

[0160] FIG12 is a flow chart of a power supply method according to an embodiment of the present invention. The following description of the power calculation method 1200 in FIG12 will be combined with the electronic device 100 in FIG1 to facilitate detailed description.

[0161] First, the controller 115 determines the relationship between the fuel voltage VFC of the fuel cell 101 and the battery voltage VBAT of the rechargeable battery 106 according to the first voltage detection signal VS1 and the second voltage detection signal VS2 (step S1210 ).

[0162] When the fuel voltage VFC is determined to be greater than the battery voltage VBAT, the controller 115 further determines whether the battery voltage VBAT exceeds a threshold voltage (step S1220). If the determination in step S1220 is yes, the driver circuit 114 turns on the first switch 103 and the relay 112 and turns off the second switch 108 (step S1230). Step S1230 is shown in FIG. 5 .

[0163] If the determination in step S1220 is negative, the controller 115 further determines whether the charging current of the rechargeable battery 106 exceeds the maximum charging current IP based on the first current detection signal IS1 (step S1240). If the determination in step S1240 is positive, the driver circuit 114 turns on the first switch 103 and the relay 112 and periodically turns on the second switch 108 (step S1250). Step S1250 is shown in FIG4. According to one embodiment of the present invention, the on-period ratio DON of the second switch 108 is as shown in Equation 2.

[0164] Returning to step S1240, if the determination in step S1240 is negative, the drive circuit 114 turns on the first switch 103, the second switch 108, and the relay 112 (step S1260). Returning to step S1210, if the determination in step S1210 is that the fuel voltage VFC is less than the battery voltage VBAT, the drive circuit 114 turns on the relay 112 and turns off the first switch 103 and the second switch 108 (step S1270). Step S1270 is shown in FIG6.

[0165] Returning to step S1210, when the controller 115 determines that the fuel voltage VFC is equal to the battery voltage VBAT, the driver circuit 114 turns on the first switch 103 and the relay 112 and turns off the second switch 108 (step S1230). After steps S1230, S1250, S1260, and S1270, the controller 115 delays for a predetermined period of time (step S1280) before returning to step S1210 to continue controlling the first switch 103, the second switch 108, and the relay 112 in response to the fuel voltage VFC and the battery voltage VBAT.

[0166] This invention proposes an electronic device and its protection method, power calculation method, and power supply method. By combining a fuel cell with a rechargeable battery, this device compensates for the fuel cell's insufficient current driving capability and improves the rechargeable battery's endurance. Furthermore, the protection method, power calculation method, and power supply method help ensure the proper operation of the fuel cell and rechargeable battery combination and provide users with reliable information about the rechargeable battery's power level, enhancing the user experience.

[0167] Although the embodiments disclosed in the present invention and their advantages have been disclosed as above, it should be understood that those skilled in the art can make changes, substitutions and processing without departing from the spirit of the invention and the scope of protection of the present invention. In addition, the scope of protection of the present invention is not limited to the processing procedures, machines, manufacturing, material compositions, devices, methods and steps in the specific embodiments described in the specification. Those skilled in the art can understand the current or future development of production processes, machines, manufacturing, material compositions, devices, methods and steps from the disclosed contents of some embodiments of the present invention. As long as they can implement substantially the same functions or obtain substantially the same results in the embodiments described herein, they can be used according to some embodiments disclosed in the present invention. Therefore, the scope of protection of the present invention includes the above-mentioned production processes, machines, manufacturing, material compositions, devices, methods and steps. In addition, each protection scope can constitute an individual embodiment, and the scope of protection of the present invention also includes the protection scope of each technical solution and the combination of embodiments.

[0168] In this specification, the present invention has been described with reference to specific embodiments thereof. However, it will be apparent that various modifications and variations may be made without departing from the spirit and scope of the present invention. Accordingly, the specification and drawings are to be regarded as illustrative rather than restrictive.

Claims

1. An electronic device, characterized in that: include: A fuel cell for providing a fuel voltage; a first switch, configured to supply the fuel voltage to the first node according to a first control signal; a rechargeable battery for providing a battery voltage; a second switch coupled to the first node, wherein the second switch charges the rechargeable battery using the fuel voltage according to a second control signal; a relay, supplying the voltage of the first node to a load according to a third control signal; A driving circuit, which generates the first control signal, the second control signal and the third control signal according to the driving signal; as well as The controller generates the driving signal according to the fuel voltage and the battery voltage.

2. The electronic device according to claim 1, wherein: When the controller determines that the fuel voltage is greater than the battery voltage and the battery voltage is not greater than a first threshold voltage, the driving circuit turns on the first switch, the second switch, and the relay.

3. The electronic device according to claim 1, wherein: When the controller determines that the fuel voltage is greater than the battery voltage and the battery voltage is greater than a first threshold voltage, the driving circuit turns on the first switch and the relay and turns off the second switch.

4. The electronic device according to claim 1, wherein: When the controller determines that the fuel voltage is lower than the battery voltage, the drive circuit turns on the relay and turns off the first switch and the second switch, wherein the rechargeable battery supplies power to the load through the external diode of the second switch.

5. The electronic device according to claim 1, wherein: When the controller determines that the fuel voltage is equal to the battery voltage, the drive circuit turns on the first switch and the relay and does not turn on the second switch, wherein the rechargeable battery supplies power to the load through the external diode of the second switch, and the fuel cell supplies power to the load through the first switch.

6. The electronic device according to claim 1, wherein: When the controller determines that the fuel voltage exceeds a first threshold voltage, the driving circuit turns off the first switch.

7. The electronic device according to claim 1, wherein: When the controller determines that the battery voltage exceeds a second threshold voltage, the driving circuit turns off the second switch.

8. The electronic device according to claim 1, wherein: Also includes: A first voltage detection circuit, configured to detect the fuel voltage and generate a first voltage detection signal; as well as The second voltage detection circuit is used to detect the battery voltage and generate a second voltage detection signal, wherein the controller determines the fuel voltage and the battery voltage according to the first voltage detection signal and the second voltage detection signal.

9. The electronic device according to claim 1, wherein: Also includes: The first current detector is coupled between the second switch and the rechargeable battery, and is used for detecting the battery current of the rechargeable battery to generate a first current detection signal.

10. The electronic device according to claim 9, wherein: When the controller determines that the fuel voltage is greater than the battery voltage and determines that the charging current of the rechargeable battery exceeds the maximum charging current based on the first current detection signal, the drive circuit turns on the first switch and the relay and periodically turns on the second switch.

11. The electronic device according to claim 9, wherein: When it is determined that the fuel voltage is greater than the battery voltage and the charging current of the rechargeable battery does not exceed the maximum charging current according to the first current detection signal, the drive circuit turns on the first switch, the second switch and the relay.

12. The electronic device according to claim 9, wherein: When the relay is not conducting, the controller calculates the power level of the rechargeable battery using an open circuit voltage method, wherein the controller further determines whether the battery current of the rechargeable battery exceeds a first current based on the first current detection signal.

13. The electronic device according to claim 12, wherein: When the battery current of the rechargeable battery exceeds the first current, the controller calculates the power of the rechargeable battery using the ampere-hour method, wherein when the battery current of the rechargeable battery does not exceed the first current, the controller calculates the power of the rechargeable battery again using the open circuit voltage method after a first predetermined time.

14. A power supply method, applicable to an electronic device, characterized in that: The electronic device includes a fuel cell, a first switch, a second switch, a rechargeable battery, and a relay, wherein the first switch is coupled between the fuel cell and a first node, the second switch is coupled between the first node and the rechargeable battery, and the relay is coupled between the first node and a load, wherein the power supply method includes: detecting a fuel voltage of the fuel cell; detecting the battery voltage of the rechargeable battery; and The first switch, the second switch, and the relay are controlled to be conductive or non-conductive according to the fuel voltage and the battery voltage.

15. The power supply method according to claim 14, wherein: The step of controlling the first switch, the second switch, and the relay to be conductive or non-conductive according to the fuel voltage and the battery voltage further includes: When the fuel voltage is greater than the battery voltage and the battery voltage is not greater than a first threshold voltage, the first switch, the second switch, and the relay are turned on.

16. The power supply method according to claim 14, wherein: The step of controlling the first switch, the second switch, and the relay to be conductive or non-conductive according to the fuel voltage and the battery voltage further includes: When the fuel voltage is greater than the battery voltage and the battery voltage is greater than a first threshold voltage, the first switch and the relay are turned on, and the second switch is turned off.

17. The power supply method according to claim 14, wherein: The step of controlling the first switch, the second switch, and the relay to be conductive or non-conductive according to the fuel voltage and the battery voltage further includes: When the fuel voltage is lower than the battery voltage, the relay is turned on and the first switch and the second switch are turned off; The rechargeable battery supplies power to the load via the external diode of the second switch.

18. The power supply method according to claim 14, wherein: The step of controlling the first switch, the second switch, and the relay to be conductive or non-conductive according to the fuel voltage and the battery voltage further includes: When the fuel voltage is equal to the battery voltage, the first switch and the relay are turned on and the second switch is turned off; The rechargeable battery supplies power to the load through the external diode of the second switch, and the fuel cell supplies power to the load through the first switch.

19. The power supply method according to claim 14, wherein: Also includes: detecting the charging current of the rechargeable battery; The step of controlling the first switch, the second switch, and the relay to be conductive or non-conductive according to the fuel voltage and the battery voltage further includes: When the fuel voltage is greater than the battery voltage and the charging current exceeds the maximum charging current, the first switch and the relay are turned on and the second switch is periodically turned on.

20. The power supply method according to claim 19, wherein: The step of controlling the first switch, the second switch, and the relay to be conductive or non-conductive according to the fuel voltage and the battery voltage further includes: When the fuel voltage is greater than the battery voltage and the charging current does not exceed the maximum charging current, the first switch, the second switch, and the relay are turned on.