Real-time clock for display screen circuit of photovoltaic inverter, display circuit and photovoltaic inverter

Abstract

According to the real-time clock for the display screen circuit of the photovoltaic inverter, the display circuit and the photovoltaic inverter provided by the invention, the energy storage module supplies power to the clock signal generation circuit under the condition that the main power supply is powered down, and the main power supply can also charge the energy storage module, so that the cycle life of the energy storage module is relatively long, and the service life of the energy storage module is prolonged. And frequent replacement is not needed, so that the operation and maintenance complexity and the economic cost of the real-time clock are reduced under the condition of ensuring normal work of the real-time clock without power failure.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of photovoltaic technology, and in particular to a real-time clock of a display screen circuit of a photovoltaic inverter, a display screen circuit and a photovoltaic inverter. BACKGROUND

[0002] In a photovoltaic inverter system, a real-time clock can be used to provide a time signal, so that the photovoltaic inverter can be accurately synchronized in actual application through the time signal, thereby ensuring the cooperation between the photovoltaic inverter and other devices and guaranteeing the stable operation of the power system.

[0003] However, the existing display screen circuit of the photovoltaic inverter includes a real-time clock circuit, and the stable operation of the display screen circuit is a prerequisite for ensuring the display effect and the charging and discharging effect of the photovoltaic inverter. However, the real-time clock of the display screen circuit of the photovoltaic inverter provided in the prior art adopts a single power supply mode, and when the main power supply of the real-time clock is powered off, the real-time clock stops working immediately. CONTENT OF THE INVENTION

[0004] The present application provides a real-time clock of a display screen circuit of a photovoltaic inverter, a display screen circuit and a photovoltaic inverter, which can be used to reduce the operation and maintenance complexity and economic cost of the real-time clock of the photovoltaic inverter.

[0005] The first aspect of the present application provides a real-time clock of a display screen circuit of a photovoltaic inverter, comprising: a clock signal generation circuit, configured to provide a clock signal; a main power supply, connected to the clock signal generation circuit, configured to supply power to the clock signal generation circuit; a crystal oscillator module, connected to the clock signal generation circuit, configured to provide a time reference signal to the clock signal generation circuit; a filter module, connected to the clock signal generation circuit, configured to filter the current input to the clock signal generation circuit; a backup power supply circuit, connected to the clock signal generation circuit, comprising an energy storage module, a current limiting module and an anti-reverse module, the backup power supply circuit being configured to supply power to the clock signal generation circuit when the main power supply is powered off; the anti-reverse module is arranged between the main power supply and the energy storage module, the main power supply charges the energy storage module through the anti-reverse module, and the anti-reverse module prevents the energy storage module from discharging to the main power supply; the current limiting module is connected between the energy storage module and the clock signal generation circuit, and is located between the anti-reverse module and the energy storage module, the energy storage module supplies power to the clock signal generation circuit through the current limiting module, and the main power supply charges the energy storage module through the current limiting module, and the current limiting module is configured to limit the current output from the energy storage module to the clock signal generation circuit and limit the current input from the main power supply to the energy storage module.

[0006] In an embodiment of the first aspect of the application, the anti-reverse module comprises a diode connected in series between the main power supply and the energy storage module.

[0007] In an embodiment of the first aspect of the application, the current limiting module comprises at least one current limiting resistor.

[0008] In an embodiment of the first aspect of the application, the energy storage module comprises a super capacitor.

[0009] In an embodiment of the first aspect of the application, the energy storage module comprises a battery.

[0010] In an embodiment of the first aspect of the application, the clock signal generation circuit comprises a real-time clock chip, the real-time clock chip comprises a first pin, a second pin, a third pin, a fourth pin, a fifth pin, a sixth pin, a seventh pin and an eighth pin, the main power supply is connected to the first pin of the real-time clock chip, and a connection point of the main power supply and the first pin is connected to the fourth capacitor and then to ground; the filter module comprises a first capacitor, one end of the first capacitor is connected to a connection point of the current limiting resistor and the eighth pin, and the other end of the first capacitor is connected to ground; the crystal oscillator module comprises a crystal oscillator, a second capacitor and a third capacitor, the crystal oscillator is used to provide a time reference signal, two ends of the crystal oscillator are respectively connected to the second pin and the third pin, one end of the second capacitor is connected to one end of the crystal oscillator, the other end of the second capacitor is connected to ground, one end of the third capacitor is connected to the other end of the crystal oscillator, and the other end of the third capacitor is connected to ground; the current limiting module is connected in series between the energy storage module and the eighth pin of the real-time clock chip, and is connected in series between the diode and the energy storage module; the fourth pin of the real-time clock chip is grounded.

[0011] The second aspect of the application provides a display circuit, comprising a master control module, a display module, and a real-time clock according to any one of the first aspect of the application; the master control module is connected to the real-time clock, receives a clock signal of the real-time clock, and converts the clock signal into a clock display control signal; the display module comprises a liquid crystal panel, and the display module receives the clock display control signal and displays a real-time time through the liquid crystal panel.

[0012] In an embodiment of the second aspect of the application, the master control module is connected to the fifth pin, the sixth pin and the seventh pin of the real-time clock chip, the master control module controls the start and stop of the action of the real-time clock chip through the fifth pin, communicates with the real-time clock chip bidirectionally through the sixth pin, and inputs a synchronous clock to the real-time clock chip through the seventh pin.

[0013] In an embodiment of the second aspect of the present application, further comprising: a low-frequency data storage for storing data of low-frequency use; and a high-frequency data storage for storing data of high-frequency use, wherein the low-frequency data storage and the high-frequency data storage are connected to the main control module respectively.

[0014] In a third aspect of the present application, a photovoltaic inverter is provided, comprising the display circuit according to any one of the second aspect of the present application, and further comprising a power parameter communication module connected to the main control module, for transmitting power parameters to the main control module, wherein the main control module converts the power parameters into power parameter display control signals, and sends the power parameter display control signals to the display module, and the display module receives the power parameter display control signals and displays the power parameters through the liquid crystal panel.

[0015] In summary, the real-time clock, the display circuit and the photovoltaic inverter for the display screen circuit of the photovoltaic inverter provided by the present application, through the energy storage module, power is supplied to the clock signal generation circuit in the case of power failure of the main power supply, and the main power supply can also charge the energy storage module, so that the cycle life of the energy storage module is longer, and the energy storage module does not need to be replaced frequently, thereby reducing the operation and maintenance complexity and economic cost of the real-time clock in the photovoltaic inverter while ensuring that the real-time clock works normally without power failure. BRIEF DESCRIPTION OF DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or prior art description will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application, and those skilled in the art can also obtain other drawings according to these drawings without creative labor.

[0017] Figure 1 The structural schematic diagram of an embodiment of the photovoltaic inverter provided by the present application.

[0018] Figure 2 The structural schematic diagram of an embodiment of the real-time clock provided by the present application.

[0019] Figure 3 The structural schematic diagram of an embodiment of the standby power supply power supply circuit provided by the present application.

[0020] Figure 4 The circuit structural schematic diagram of an embodiment of the real-time clock provided by the present application.

[0021] Figure 5 The structural schematic diagram of another embodiment of the photovoltaic inverter provided by the present application.

[0022] The specific embodiments of the present application have been shown by the above drawings, and will be described in more detail hereinafter. These drawings and the written description are not intended to restrict the scope of the present application in any way, but to explain the present application to those skilled in the art by referring to specific embodiments. DETAILED DESCRIPTION

[0023] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present application.

[0024] The terms "first", "second", "third", "fourth" and the like (if any) in the specification and claims of the present application and the above drawings are used to distinguish similar objects, and do not necessarily indicate a specific order or a chronological sequence. It should be understood that the data thus used can be interchanged under appropriate circumstances, so that the embodiments of the present application described herein can be implemented in an order other than that illustrated or described herein. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion, for example, a process, method, system, product or device including a series of steps or units does not necessarily have to be limited to those steps or units clearly listed, but can include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0025] A photovoltaic inverter is the core equipment of a solar power generation system, undertakes the key task of converting direct current generated by photovoltaic modules into alternating current, and has functions such as maximum power point tracking, system protection and intelligent control, and is the key to stable operation of a photovoltaic system.

[0026] In a specific implementation, a photovoltaic inverter realizes power conversion through a boost circuit and an inverter bridge circuit. The boost circuit boosts low-voltage direct current output by photovoltaic modules to high-voltage direct current required for inversion; the inverter bridge circuit uses high-frequency pulse width modulation technology to convert the boosted direct current into alternating current close to a sine wave. This process involves accurate control of power electronic switches, and through the fast on-off of switching elements, a pulse train is formed, and then smoothed by a filter to form stable alternating current, ensuring the stability and waveform quality of the output voltage.

[0027] More specifically, the display screen of the photovoltaic inverter needs to display the power generation time, power parameters and other information in real time in some cases to ensure that the user accurately monitors the system operation state. Among them, the display screen circuit can not only display the accurate time for the user at the moment, but also provide the current time to the control chip of the photovoltaic inverter after the photovoltaic inverter is powered on again, so that it can be connected to the power grid within the pre-set time period. Especially for the area not connected to the network, if the time obtained by the inverter deviates from the local time, the grid connection operation is performed in the time period not allowed to be connected to the grid, which will cause loss to the customer.

[0028] For example, Figure 1 The structure schematic diagram of an embodiment of the photovoltaic inverter provided in the present application is shown in FIG. 1. Figure 1 The photovoltaic inverter 1 shown in FIG. 1 includes a real-time clock 10. The real-time clock 10 can be used to provide a clock signal, so that the display screen in the photovoltaic inverter 1 displays time based on the clock signal or other devices perform relevant synchronization operations based on the clock signal, etc.

[0029] In the prior art, the real-time clock 10 in the photovoltaic inverter 1 usually uses a 3.3V direct current voltage as the main power supply and a CR2032 lithium-manganese battery or other button cell as the power-off backup power supply. Among them, when the main power supply is normally working, the real-time clock is directly powered by the main power supply, and when the main power supply is powered off, the button cell supplies power to the clock circuit to maintain its operation.

[0030] However, since the service life of the button cell is limited, it needs to be replaced regularly during the long-term operation of the photovoltaic inverter, which greatly increases the maintenance cost of the photovoltaic inverter, especially in remote areas or large photovoltaic power stations, the operation cost is significantly increased.

[0031] Based on this, the present application provides a real-time clock for a display screen circuit of a photovoltaic inverter and a photovoltaic inverter, which can be used to reduce the operation and maintenance complexity and economic cost of the real-time clock in the photovoltaic inverter. The technical solutions of the present application will be described in detail below with specific embodiments. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described in detail in some embodiments.

[0032] Figure 2 The structure schematic diagram of an embodiment of the real-time clock provided in the present application is shown in FIG. 2. Figure 2 The real-time clock shown in FIG. 2 can be applied to the display screen circuit of the photovoltaic inverter 1 shown in FIG. 1, specifically, the real-time clock 10 shown in FIG. 1. Figure 1 Figure 2 The real-time clock 10 shown in FIG. 1 includes:

[0033] The clock signal generation circuit 100 is used to provide a real-time clock signal. In an embodiment, the clock signal generation circuit 100 can be a low-power clock signal generation circuit such as DS1302, etc.​

[0034] The main power supply 101 is connected to the clock signal generation circuit 100 for supplying power to the clock signal generation circuit 100. In one embodiment, the main power supply 101 can be used to provide a direct current voltage of 3.3V.

[0035] The backup power supply circuit 102 is connected to the clock signal generation circuit 100 for supplying power to the clock signal generation circuit 100 in place of the main power supply 101 when the main power supply 101 is powered off.

[0036] The crystal oscillator module 103 is connected to the clock signal generation circuit 100 for providing a time reference signal to the clock signal generation circuit 100.

[0037] The filter module 104 is connected to the clock signal generation circuit 100 for filtering the current input to the clock signal generation circuit 100.

[0038] Further, Figure 3 The backup power supply circuit 102 is connected to the clock signal generation circuit 100 for supplying power to the clock signal generation circuit 100 in place of the main power supply 101 when the main power supply 101 is powered off. Figure 3 The backup power supply circuit 102 is connected to the clock signal generation circuit 100 for supplying power to the clock signal generation circuit 100 in place of the main power supply 101 when the main power supply 101 is powered off. Figure 2 The backup power supply circuit 102 is connected to the clock signal generation circuit 100 for supplying power to the clock signal generation circuit 100 in place of the main power supply 101 when the main power supply 101 is powered off. Figure 3 The backup power supply circuit 102 is connected to the clock signal generation circuit 100 for supplying power to the clock signal generation circuit 100 in place of the main power supply 101 when the main power supply 101 is powered off.

[0039] The energy storage module 1021 is used to store energy. In one embodiment, the energy storage module 1021 can be a super capacitor C60, and specifically a super capacitor C60 with a capacitance of 0.1-0.2F. Alternatively, the energy storage module can also be a battery.

[0040] The reverse prevention module 1022 is connected between the main power supply 101 and the energy storage module 1021, and the main power supply 101 charges the energy storage module 1021 through the reverse prevention module 1022, and the energy storage module 1021 is prevented from discharging to the main power supply 101.

[0041] The current limiting module 1023 is connected between the energy storage module 1021 and the clock signal generation circuit 100, and is located between the reverse prevention module 1022 and the energy storage module 1021. The energy storage module 1021 supplies power to the clock signal generation circuit 100 through the current limiting module 1023, and the main power supply 101 charges the energy storage module 1021 through the current limiting module 1023. The current limiting module 1023 can be used to limit the size of the current output by the energy storage module 1021 to the clock signal generation circuit 100, to prevent the clock signal generation circuit 100 from being damaged by overcurrent, and to limit the size of the current input by the main power supply 101 to the energy storage module 1021 when the main power supply 101 charges the energy storage module 1021, to prevent the energy storage module 1021 from being damaged by overcurrent.

[0042] It can be understood that when the main power supply 101 is normally powered, the main power supply 101 can simultaneously supply power for the clock signal generation circuit 100 and charge the energy storage module 1021. Even if the energy storage module 1021 is exhausted after the device is powered off for a long time, the energy storage module 1021 can be charged again when the main power supply 101 is powered on next time.

[0043] In summary, the real-time clock 10 applicable to the photovoltaic inverter 1 provided in the application supplies power for the clock signal generation circuit 100 in the case that the main power supply 101 is powered off through the energy storage module 1021, and the main power supply 101 can also charge the energy storage module 1021. Since the cycle life of the energy storage module 1021 is relatively long, the energy storage module 1021 does not need to be frequently replaced, thereby reducing the operation and maintenance complexity and economic cost of the real-time clock 10 in the photovoltaic inverter 1 in the case that the real-time clock 10 is continuously powered and normally works.

[0044] Further, when the energy storage module 1021 is a super capacitor, the working temperature range is larger, which can be more suitable for extreme environments, so that the real-time clock 10 and the photovoltaic inverter 1 where the real-time clock 10 is located have stronger stability and safety, and can be applied to more scenes.

[0045] Figure 4 The circuit structure schematic diagram of an embodiment of the real-time clock provided in the application is as shown in Figure 4 It is shown that Figure 2 The real-time clock 10 provided in the application is one specific circuit implementation manner, and the circuit structure of the real-time clock provided in the embodiment will be described below. Figure 4 The circuit structure of the real-time clock provided in the embodiment will be described below.

[0046] As shown in Figure 4 The clock signal generation circuit 100 includes a real-time clock chip, which is marked as U15 and includes eight pins, which are a first pin, a second pin, a third pin, a fourth pin, a fifth pin, a sixth pin, a seventh pin and an eighth pin in sequence. Figure 4 In the embodiment, the first pin is marked as 1, the second pin is marked as 2, the third pin is marked as 3, the fourth pin is marked as 4, the fifth pin is marked as 5, the sixth pin is marked as 6, the seventh pin is marked as 7 and the eighth pin is marked as 8. Among them:

[0047] The first pin is used for connecting the main power supply 101 and receiving direct current provided by the main power supply 101, and the voltage range of the direct current is 2-5V.

[0048] The second pin and the third pin are used for receiving a time reference signal, wherein the time reference signal is a stable oscillation frequency, and the oscillation frequency is provided by a crystal oscillator Y2. The parallel connection of a resistor on the crystal oscillator Y2 can ensure the oscillation of the crystal oscillator, thereby improving the start-up reliability of the circuit when the circuit is powered on and different power supplies are switched.

[0049] The fourth pin is used to connect to the reference ground (GND).

[0050] Pin 5 is used to receive the reset signal RST.

[0051] The sixth pin is an input / output (I / O) interface used for data transmission. The MCU can send a read time command to the clock signal generation circuit 100 through the sixth pin. The clock signal generation circuit 100 can also send real-time time to the microcontroller through the sixth pin.

[0052] Pin 7 is used to input the clock signal SCLK, which indicates the current real-time time. In one specific implementation, the clock signal generation circuit 100 reads data based on the rising edge of the clock signal SCLK pulse and sends data on the falling edge of the pulse.

[0053] The eighth pin is used to connect to the backup power supply circuit 102 and receive DC power from the supercapacitor C60, which serves as the energy storage module 1021 in the backup power supply circuit 102.

[0054] In one embodiment, such as Figure 4 In the backup power supply circuit 102 of the real-time clock 10 shown, the anti-reverse module 1022 includes: a diode D26, which is forward connected between the main power supply 101 and the energy storage module 1021. The anti-reverse module 1022 is used to prevent the energy storage module 1021 from discharging to the main power supply 101. In this embodiment, the energy storage module 1021 is a supercapacitor C60.

[0055] Diode D26 is used to prevent the current of the energy storage module 1021 from flowing back to the main power supply 101 when the main power supply 101 is powered off, ensuring the unidirectionality and stability of the backup power supply circuit 102. The unidirectional conduction characteristic of diode D26 optimizes the reliability of the power transmission path in the real-time clock 10.

[0056] For example, the diode D26 in the anti-reverse module 100 can specifically be a BAT54S Schottky diode. The BAT54S Schottky diode has a small voltage drop and low leakage current when conducting, resulting in less loss compared to traditional diodes. Combined with... Figure 4 In the example shown, one end of diode D26 is connected to main power supply 101 through resistor R68 to receive a DC voltage of 3.3V provided by main power supply 101, and the other end of diode D26 is connected to the eighth pin of the real-time clock chip.

[0057] When the main power supply 101 is normally powered, the voltage provided by the main power supply 101 is direct current of 3.3V, which is charged to the energy storage module 1021 through the diode D26; when the main power supply 101 is powered off and cannot normally supply power, the voltage provided by the energy storage module 1021 cannot be output to the side of the main power supply 101 in reverse through the diode D26.

[0058] In an embodiment, as shown in the standby power supply power supply circuit 102 of the real-time clock 10, the current limiting module 1023 includes at least one current limiting resistor R69 connected between the energy storage module 1021 and the clock signal generation circuit and located between the anti-reverse module 1022 and the energy storage module 1021, for limiting the current output by the energy storage module 1021 and limiting the current input to the energy storage module 1021 by the main power supply 101. Figure 4

[0059] For example, as shown in the current limiting module 1023, it includes a current limiting resistor R69, one end of the current limiting resistor R69 is connected to the energy storage module 1021, the other end is connected to the eighth pin of the real-time clock chip, and the current limiting resistor R69 is connected in series between the diode D26 and the energy storage module 1021. In this embodiment, the energy storage module 1021 is a super capacitor C60. For another example, the current limiting module 1023 can also include a plurality of current limiting resistors R69 connected in parallel. Figure 4

[0060] In an embodiment, as shown in the real-time clock 10, the real-time clock 10 further includes a crystal oscillator module for providing a time reference signal to the clock signal generation circuit 100, and the time reference signal is a stable oscillation frequency. Figure 4

[0061] For example, as shown in the standby power supply power supply circuit 102 of the real-time clock 10, the crystal oscillator module includes a crystal oscillator Y2, a second capacitor C20 and a third capacitor C21, the crystal oscillator Y2 has two ends connected to the second pin and the third pin respectively, and the crystal oscillator Y2 provides a stable time reference signal to the clock signal generation circuit 100, so that the clock signal generation circuit 100 can be used to realize the function of real-time clocking. The second capacitor C20 has one end connected to one end of the crystal oscillator Y2, and the other end of the second capacitor C20 is grounded; the third capacitor C21 has one end connected to the other end of the crystal oscillator Y2, and the other end of the third capacitor C21 is grounded. The second capacitor C20 and the third capacitor C21 mainly function to form an oscillation loop with the crystal oscillator Y2 in the circuit, so as to stabilize the oscillation frequency and ensure the reliable work of the crystal oscillator Y2. Figure 4 The filter module 104 includes a first capacitor C51, one end of the first capacitor C51 is connected to the connection point of the current limiting resistor R69 and the eighth pin, and the other end is grounded. The filter module 104 is used for filtering the current input to the clock signal generation circuit.

[0062]

[0063] ​​​​The main power supply 101 is connected to the first pin of the real-time clock chip, and the connection point of the main power supply 101 and the first pin is connected to the fourth capacitor C19 and then grounded, and the fourth pin of the real-time clock chip is grounded.

[0064] The fourth capacitor C19 has the function of storing energy, and can provide temporary power for a period of time when the main power supply 101 is powered off, ensuring that the real-time clock chip continues to operate.

[0065] Figure 5 The structure diagram of another embodiment of the photovoltaic inverter provided in the present application is shown in FIG. 2. Figure 5 As shown in FIG. 2, in an embodiment, the present application further provides a display circuit in the photovoltaic inverter 1, which comprises the above-mentioned real-time clock 10, and a master control module 11 and a display module 12; the master control module 11 is connected to the real-time clock 10 to receive the clock signal of the real-time clock 10, and convert the clock signal into a clock display control signal; the display module 12 comprises a liquid crystal panel, and the display module 12 receives the clock display control signal to display the real-time time through the liquid crystal panel.

[0066] The display module 12 extracts the time in the display control signal, converts it into a display string, controls the dot display on the liquid crystal display screen, and thus displays the real-time time on the liquid crystal panel.

[0067] The master control module 11 is connected to the fifth pin, the sixth pin and the seventh pin of the real-time clock chip, the master control module 11 controls the start and stop of the action of the real-time clock chip through the fifth pin, communicates with the real-time clock chip bidirectionally through the sixth pin, and inputs a synchronous clock to the real-time clock chip through the seventh pin.

[0068] In an embodiment, the master control module 11 is a microcontroller, which is responsible for processing display data, managing interface communication and coordinating display operation. The microcontroller controls the start and stop of the action of the real-time clock chip through the fifth pin, and the instructions of the sixth pin and the seventh pin are activated only when the fifth pin is pulled high. The microcontroller sends a command byte to the real-time clock chip through the sixth pin to determine whether the data is written into the real-time clock chip or read from the real-time clock chip.

[0069] In an embodiment, the display circuit in the photovoltaic inverter 1 shown in FIG. 2 further comprises: Figure 5

[0070] A low-frequency data storage 15 for storing data used at low frequency;

[0071] A high-frequency data storage 14 for storing data used at high frequency;

[0072] The low-frequency data storage 15 and the high-frequency data storage 14 are respectively connected to the master control module 11.

[0073] ​The high-frequency data storage 14 can be an electrically erasable programmable read-only memory (EEPROM), in this embodiment, a 24LC64T chip, used in the display circuit of the photovoltaic inverter 1 to store data used at high frequency, such as inverter configuration parameters, calibration data and coefficients, operation statistics, etc.

[0074] The low-frequency data storage 15 can be a non-volatile memory device (Flash memory), in this embodiment, a W25Q32 chip, used in the display circuit of the photovoltaic inverter 1 to store data used at low frequency, such as historical data, event logs, power generation reports, resource files, etc.

[0075] In one embodiment, the application also provides a photovoltaic inverter, comprising Figure 5 As shown in the photovoltaic inverter 1, the photovoltaic inverter 1 provided in this embodiment comprises the above display circuit, and further comprises a power parameter communication module 13, wherein the power parameter communication module 13 is connected with the main control module 11, and is used to transmit power parameters to the main control module 11; the main control module 11 converts the power parameters into power parameter display control signals, and sends the power parameter display control signals to the display module 12; the display module 12 receives the power parameter display control signals, and displays the power parameters through the liquid crystal panel.

[0076] The power parameters include current data, voltage data, etc. The power parameter communication module transmits analog signals to the main control module; the main control module 11 converts the analog signals into digital signals through filtering, physical quantity conversion, data calculation, etc., and inputs the digital signals to the display module 12; the display module 12 receives the digital signals to extract current, voltage, etc., converts the values into display strings, and controls the pixel points on the liquid crystal display screen to display, so as to display the power parameters on the liquid crystal panel.

[0077] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the application, but not to limit them; although the application has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions recorded in the above embodiments, or make equivalent replacement for part or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the application.

Claims

1. A real-time clock for a display screen circuit of a photovoltaic inverter, characterized in that The application relates to a real-time clock, which comprises the following parts: a clock signal generating circuit for providing a clock signal; a main power supply connected to the clock signal generating circuit for supplying power to the clock signal generating circuit; a crystal oscillator module connected to the clock signal generating circuit for providing a time reference signal to the clock signal generating circuit; a filter module connected to the clock signal generating circuit for filtering the current input to the clock signal generating circuit; a backup power supply circuit connected to the clock signal generating circuit, which comprises an energy storage module, a current limiting module and an anti-reverse module, and is used for supplying power to the clock signal generating circuit when the main power supply is powered off; the anti-reverse module is arranged between the main power supply and the energy storage module, the main power supply charges the energy storage module through the anti-reverse module, and the energy storage module is prevented from discharging to the main power supply; the current limiting module is connected between the energy storage module and the clock signal generating circuit and is arranged between the anti-reverse module and the energy storage module, the energy storage module supplies power to the clock signal generating circuit through the current limiting module, and the main power supply charges the energy storage module through the current limiting module, and the current limiting module is used for limiting the current output from the energy storage module to the clock signal generating circuit and limiting the current input from the main power supply to the energy storage module.

2. The real-time clock of claim 1, wherein, The anti-reverse module comprises a diode, and the diode is connected in a forward direction between the main power supply and the energy storage module.

3. The real-time clock of claim 1, wherein, The current limiting module comprises at least one current limiting resistor.

4. The real-time clock of claim 1, wherein, The energy storage module comprises a super capacitor.

5. The real-time clock of claim 1, wherein, The energy storage module comprises a battery.

6. The real-time clock according to any one of claims 1 to 5, characterized in that The clock signal generating circuit comprises a real-time clock chip, the real-time clock chip comprises a first pin, a second pin, a third pin, a fourth pin, a fifth pin, a sixth pin, a seventh pin and an eighth pin, the main power supply is connected to the first pin of the real-time clock chip, a connection point of the main power supply and the first pin is connected to a fourth capacitor and then to the ground, the filter module comprises a first capacitor, one end of the first capacitor is connected to a connection point of a current limiting resistor and the eighth pin, and the other end of the first capacitor is connected to the ground, the crystal oscillator module comprises a crystal oscillator, a second capacitor and a third capacitor, the crystal oscillator is used for providing a time reference signal, two ends of the crystal oscillator are respectively connected to the second pin and the third pin, one end of the second capacitor is connected to one end of the crystal oscillator, the other end of the second capacitor is connected to the ground, one end of the third capacitor is connected to the other end of the crystal oscillator, and the other end of the third capacitor is connected to the ground, the current limiting module is connected in series between the energy storage module and the eighth pin of the real-time clock chip and is connected in series between the diode and the energy storage module, and the fourth pin of the real-time clock chip is grounded.

7. A display circuit, characterized by The application further relates to a real-time clock display device, which comprises a main control module, a display module and a real-time clock as described in any one of claims 1 to 6. The main control module is connected to the real-time clock, receives the clock signal of the real-time clock, converts the clock signal into a clock display control signal, and transmits the clock display control signal to the display module. The display module comprises a liquid crystal panel, receives the clock display control signal, and displays the real-time time through the liquid crystal panel.

8. The display circuit of claim 7, wherein, The master module is connected with the fifth pin, the sixth pin and the seventh pin of the real-time clock chip, the master module controls the start and stop of the real-time clock chip through the fifth pin, communicates with the real-time clock chip through the sixth pin, and inputs the synchronous clock to the real-time clock chip through the seventh pin.

9. The display circuit of claim 7, wherein, Further comprising: a low-frequency data storage for storing data used at low frequency; a high-frequency data storage for storing data used at high frequency, the low-frequency data storage and the high-frequency data storage being connected with the master module respectively.

10. A photovoltaic inverter, characterized by The display circuit comprises the display circuit according to any one of claims 6-8, and further comprises a power parameter communication module connected with the master module, for transmitting power parameters to the master module, the master module converting the power parameters into power parameter display control signals and sending the power parameter display control signals to the display module, and the display module receiving the power parameter display control signals and displaying the power parameters through the liquid crystal panel.

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