Resistive load direct current circuit and application of resistive load direct current circuit in electric appliance manufacturing

Abstract

The invention relates to a resistive load direct-current circuit, the resistive load direct-current circuit at least comprises a power switch, a resistive load and an electric appliance controller, and the electric appliance controller at least comprises a relay control panel and an electromagnetic valve; the resistive load is loaded between two poles of the power switch, and the power switch is also connected with the electric appliance controller; wherein an arc extinguishing module is additionally arranged on a loop of the resistive load and the power switch, and the arc extinguishing module is used for eliminating an arc discharge phenomenon occurring at an on-off moment of the power switch; the power switch is a high-frequency flyback power switch; the electromagnetic valve is a direct-current electromagnetic valve. According to the invention, direct-current transformation of the load is realized by replacing devices and changing circuits, so that a heating resistive load transformation design scheme of a zero-carbon power supply station is provided, and guarantee is provided for high-reliability power supply and safe and stable operation of a whole set of optical storage direct-current flexible system.

Description

Technical Field

[0001] The present application relates to the technical field of DC home appliance transformation, and in particular to a resistive load DC circuit and its application in electrical appliance manufacturing. Background Art

[0002] At present, with the rapid development and increasing popularity of new energy technologies, wind power generation and photovoltaic power generation, as important components of renewable energy, are becoming more and more widely used in various industries. More and more power supply stations are also using wind power generation and photovoltaic power generation technologies to reduce energy costs. Therefore, the development of smart home appliances based on DC power supply has gradually become a future development trend.

[0003] However, the problems caused by this are becoming increasingly prominent, such as the problem of power utilization. If some AC household appliances are directly connected to DC power, some problems will appear: for example, since DC has no zero-crossing characteristics, resistive loads will have arcing during the disconnection process; and AC coils and AC motors cannot use DC power supply. The existing arc extinguishing methods include mechanical arc extinguishing method and magnetic arc extinguishing method, which are not suitable for direct action in the circuit.

[0004] Application Contents

[0005] In order to solve the above problems, the present application provides a resistive load DC circuit and its application in electrical appliance manufacturing, aiming to solve the problem of photovoltaic self-generation and self-use in the existing photovoltaic storage direct-flexible system, so as to realize the priority consumption of photovoltaic DC power through DC load and improve the utilization rate of electric energy.

[0006] This application adopts the following technical solutions:

[0007] In a first aspect, the present application provides a resistive load DC circuit, the resistive DC load circuit at least comprising: a power switch, a resistive load and an electrical controller, the electrical controller at least comprising: a relay control board and a solenoid valve; the resistive load is loaded between the two poles of the power switch, and the power switch is also connected to the electrical controller; wherein:

[0008] An arc extinguishing module is added to the circuit of the resistive load and the power switch, and the arc extinguishing module is used to eliminate the arcing phenomenon that occurs when the power switch is turned on and off;

[0009] The power switch is a high-frequency flyback power switch;

[0010] The solenoid valve is a DC solenoid valve.

[0011] Optionally, in the resistive load DC circuit described above, the arc extinguishing module at least includes: a power conversion circuit, an arc extinguishing circuit, and a main control chip;

[0012] The arc extinguishing circuit is connected in series to the loop of the resistive load and the power switch;

[0013] The power conversion circuit is connected in parallel to the two poles of the power switch. The power conversion circuit is a flyback buck circuit, which is used to take power from the power bus and convert the power into a specified low-voltage power to supply to the main control chip;

[0014] The main control chip is electrically connected to the arc extinguishing circuit, and the main control chip is used to drive the arc extinguishing circuit.

[0015] Optionally, in the above-mentioned resistive load DC circuit, the arc extinguishing module further includes: a bus voltage detection circuit, an external trigger circuit, a communication circuit, a flexible grounding circuit, and a sensor circuit, and the bus voltage detection circuit, the external trigger circuit, the communication circuit, the flexible grounding circuit, and the sensor circuit are respectively connected to the main control chip;

[0016] Among them, the flexible grounding circuit is used to connect to the flexible grounding system, the communication circuit is used to connect to the communication system, the sensor circuit is used to connect to the temperature sensor, the bus voltage detection circuit is used to connect to the bus voltage detection system, and the external trigger circuit is used to receive an external trigger signal.

[0017] Optionally, in the resistive load DC circuit described above, the arc extinguishing circuit includes a first driving branch, a second driving branch and a switching branch;

[0018] The first driving branch and the second driving branch are respectively used to amplify, convert and perform voltage stabilization protection on the driving signal in sequence, so as to respectively control at least part of the on-off branch.

[0019] Optionally, in the resistive load DC circuit, the first driving branch includes: a first resistor, a second resistor, a first optocoupler, a first NPN transistor, a first PNP transistor, a third resistor, a fourth resistor, a first voltage regulator, and a fifth resistor;

[0020] One end of the first resistor is connected to the driving signal, and the other end of the first resistor is respectively connected to the first pin of the first optical coupler and one end of the second resistor;

[0021] The other end of the second resistor is connected to the second pin of the first optical coupler and is grounded;

[0022] The third pin of the first optical coupler is respectively connected to the control end of the first NPN transistor, the control end of the first PNP transistor and one end of the fourth resistor;

[0023] The fourth pin of the first optical coupler is connected to the input end of the first NPN transistor;

[0024] The output end of the first NPN transistor is respectively connected to one end of the third resistor and the input end of the first PNP transistor;

[0025] The other end of the fourth resistor is respectively connected to the output end of the first PNP transistor, the anode of the first voltage regulator tube and one end of the fifth resistor and is connected to the signal ground line;

[0026] The other end of the third resistor is respectively connected to the cathode of the first voltage regulator tube, and the other end of the fifth resistor is connected to the on-off branch as the output end of the first driving branch.

[0027] Optionally, in the resistive load DC circuit, the second driving branch includes: a sixth resistor, a seventh resistor, a second optocoupler, a second NPN transistor, a second PNP transistor, an eighth resistor, a ninth resistor, a second voltage regulator, and a tenth resistor;

[0028] One end of the sixth resistor is connected to the driving signal, and the other end of the sixth resistor is respectively connected to the first pin of the second optical coupler and one end of the seventh resistor;

[0029] The other end of the seventh resistor is connected to the second pin of the second optical coupler and is grounded;

[0030] The third pin of the second optical coupler is respectively connected to the control end of the second NPN transistor, the control end of the second PNP transistor and one end of the ninth resistor;

[0031] The fourth pin of the second optical coupler is connected to the input end of the second NPN transistor;

[0032] The output end of the second NPN transistor is respectively connected to one end of the eighth resistor and the input end of the second PNP transistor;

[0033] The other end of the ninth resistor is respectively connected to the output end of the second PNP transistor, the anode of the second voltage regulator tube and one end of the tenth resistor and is connected to the signal ground line;

[0034] The other end of the eighth resistor is respectively connected to the cathode of the second voltage regulator tube, and the other end of the tenth resistor is connected to the on-off branch as the output end of the second driving branch.

[0035] Optionally, in the resistive load DC circuit described above, the on-off branch includes: two first field effect transistors and a second field effect transistor connected in parallel;

[0036] The first field effect transistor is connected to the output end of the second driving branch;

[0037] The second field effect transistor is connected to the output end of the first driving branch;

[0038] A parallel connection point of the first field effect transistor and the second field effect transistor is connected in series to a loop of the resistive load and the power switch.

[0039] Optionally, in the above-mentioned resistive load DC circuit, the first field effect transistor and the second field effect transistor are CI30N120SM tubes.

[0040] Optionally, in the resistive load DC circuit mentioned above, the DC solenoid valve is 24V.

[0041] In a second aspect, the present application provides an application of the above-mentioned resistive load DC circuit in electrical appliance manufacturing.

[0042] At least one of the above technical solutions adopted in this application can achieve the following beneficial effects:

[0043] This application realizes the DC transformation of loads by replacing devices and changing circuits, thereby providing a design solution for the transformation of heating resistive loads in a zero-carbon power supply station, and providing guarantee for the high-reliability power supply and safe and stable operation of the entire photovoltaic storage direct-flexible system. From a system perspective, this application brings effective and convenient load absorption to the photovoltaic storage direct-flexible system, which absorbs loads on site and significantly improves the utilization rate of photovoltaics; the DC application of necessary loads saves energy and reduces electricity costs; resistive loads can flexibly adjust the output power according to the DC bus voltage and calmly face bus fluctuations; and reduce energy conversion losses in the system. From a product-level product perspective, this application replaces the original AC step-down solution and adopts a switching power supply module to reduce the size and noise of the transformer and reduce costs; solves the problem of arcing in DC resistive load switches, avoids the burning and damage caused by arcing, and has the characteristics of high stability and high reliability; reduces the risk of electric shock. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0045] Figure 1 The topology diagram of a commercial water boiler circuit with a resistive load of a zero-carbon power supply station according to the prior art is shown;

[0046] Figure 2 A topological diagram of a water boiler circuit of a heating type resistive load of a zero-carbon power supply station according to an embodiment of the present application is shown;

[0047] Figure 3A schematic structural diagram of an arc extinguishing module according to an embodiment of the present application is shown;

[0048] Figure 4 A schematic structural diagram of an arc extinguishing circuit according to an embodiment of the present application is shown;

[0049] Figure 5 A schematic structural diagram of an optical coupler according to an embodiment of the present application is shown. DETAILED DESCRIPTION

[0050] The exemplary embodiments of the present application will be described in more detail below. However, it should be understood that the present application can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided to enable a more thorough understanding of the present application and to enable the scope of the present application to be fully communicated to those skilled in the art.

[0051] The disclosure of the present application provides many different embodiments or examples to realize the different structures of the present application. In order to simplify the disclosure of the present application, the parts and settings of specific examples are described in the present application. Of course, they are only examples, and the purpose is not to limit the present application. In addition, the present application can repeat reference numbers and / or reference letters in different examples, and this repetition is for the purpose of simplification and clarity, and does not indicate the relationship between the various embodiments and / or settings discussed in itself. In addition, the various specific processes and material examples provided by the present application, but those of ordinary skill in the art can be aware of the application of other processes and / or the use of other materials.

[0052] Typically, the term can be understood at least in part based on the usage of the above application. For example, the term "one or more" used in the present application depends at least in part on the above application, and can be used to describe any component, structure or feature in the singular, or can be used to describe a combination of components, structures or features in the plural. Similarly, terms such as "one", "an" or "the" can also be understood at least in part to convey singular usage or convey plural usage depending on the above application. In addition, the term "based on..." can be understood as not necessarily intended to convey a set of exclusive factors, but can alternatively, at least in part, depend on the context, allowing the presence of additional factors that do not necessarily have to be explicitly described.

[0053] It should be noted that, in the description of the present application, the meanings of the terms "on", "over", "above", "over", etc. should be interpreted in the broadest way, meaning that the description containing these terms is interpreted as "the component can be set on another component in direct contact, or there can be intermediate components or layers between the components."

[0054] For ease of description, the present application may also use spatially relative terms such as "under", "beneath", "below", "under", "upper", "lower", etc. to describe the relationship of one component to another component shown in the drawings. In addition to the orientations described in the drawings, the spatially relative terms are also intended to cover different orientations of the device in use or operation. The device can be oriented in other ways, and the spatially relative descriptions used in the present application can be interpreted accordingly.

[0055] For the convenience of description, the present application may also use quantitative relative terms such as "first", "second", "third", etc. to describe the difference between one component and another component. Such terms are only used to distinguish different devices.

[0056] The development of smart home appliances based on DC power supply is gradually becoming a future development trend. The current transformation of traditional loads is of great significance to the future technical breakthroughs in DC power supply and DC home appliances.

[0057] The idea of ​​this application is to solve the problem of photovoltaic self-generation and self-use in the existing photovoltaic storage direct-flexible system. The direct current generated by photovoltaics is preferentially consumed by the direct current load to improve the utilization rate of electric energy. Specifically, the current loads consumed by the 750V DC bus include DC charging piles, DC inverters, central air conditioners, etc., while there is no product-level planning for the consumption loads (DC appliances) of the household 220V DC bus. In order to solve the arcing problem of resistive heating loads when DC power is supplied and the device adaptation problem, this application specifically proposes a resistive load DC circuit.

[0058] Specifically, the present application provides a resistive load DC circuit, which at least includes: a power switch, a resistive load and an electrical controller, and the electrical controller at least includes: a relay control board and a solenoid valve; the resistive load is loaded between the two poles of the power switch, and the power switch is also connected to the electrical controller; wherein an arc extinguishing module is added to the circuit between the resistive load and the power switch, and the arc extinguishing module is used to eliminate the arcing phenomenon that occurs when the power switch is turned on and off; the power switch is a high-frequency flyback power switch; and the solenoid valve is a DC solenoid valve.

[0059] The following is a specific example, taking the internal circuit topology of a commercial AC water heater as an example, to screen the internal power frequency step-down circuit, AC solenoid valve, resistive heating circuit, etc., which cannot be directly powered by DC. Please refer to Figure 1 , Figure 1 The topology diagram of a commercial water boiler circuit with a zero-carbon power supply and a heating type resistive load according to the prior art is shown. Figure 1It can be seen that it is mainly composed of power board (power switch), controller (main control circuit of electrical appliances), relay module, heating resistor wire, display screen, communication module, touch button, water inlet and outlet solenoid valve, detection sensor, pressure switch, etc. The power conversion circuit of the power switch is mainly composed of power frequency transformer step-down combined rectification and voltage stabilization.

[0060] After analysis, it was found that: Figure 1 Based on the circuit structure shown, if direct current is used for power supply, the two ends of the power frequency transformer will be directly short-circuited, so the power supply scheme needs to be replaced; the original relay module is mainly used to control the heating resistor wire, and the relay switches the heating circuit. The heating circuit is powered by AC220V input. If it is powered by DC, since DC has no zero-crossing characteristics, the switch will arc at the moment of switching on and off, causing fire or personal injury, and the degree of arcing is affected by the resistive load power; the original AC220V solenoid valve essentially allows the AC coil to be energized and then generates magnetic force. The internal resistance is very small and it will burn out directly if it is powered by DC, so it also needs to be further modified; the remaining touch buttons, communication modules, display circuits, and pressure switches are all powered by the stepped-down DC24V, and the detection sensors output small voltage signals, which do not need to be considered during the transformation process.

[0061] Please refer to the circuit topology diagram after modification Figure 2 ,like Figure 2 As shown, Figure 2 The topology diagram of the water boiler circuit of the heating type resistive load of the zero-carbon power supply station according to an embodiment of the present application is shown. Figure 2 It can be seen that this embodiment uses DC power supply. Figure 1 The structure given has been transformed in three aspects. First, a high-frequency flyback power switch is used to replace the original power supply solution. The power switch is rectified first and then stepped down at high frequency, and has a wide voltage input range (specifically, it can be but not limited to DC120V-DC373V). It can specifically support DC220V input and output a specified voltage, such as DC24V voltage power supply to the controller of the electrical appliance. In actual scenarios, a 220V to 24V switching power supply is usually used to replace the power frequency step-down circuit. Second, a DC solenoid valve is selected to replace the original AC solenoid valve. In some embodiments, a 24V DC solenoid valve can be used to replace the original AC solenoid valve. In actual scenarios, the selection of a DC solenoid valve usually changes the voltage level but does not change the power. Third, an arc extinguishing module is added to the circuit of the resistive load and the power switch. The arc extinguishing module is used to eliminate the arcing phenomenon that occurs when the power switch is turned on and off, that is, the arc extinguishing module is connected in series in the control circuit of the heating resistor relay, and the arc is quickly extinguished at the moment of the relay opening and closing. Its main principle is to simulate the AC zero-crossing characteristics through the internal IGBT switch device, thereby destroying the arcing conditions and achieving the effect of arc extinguishing. The rest does not need to be changed.

[0062] It is recommended that the arc extinguishing module be connected in series to the circuit of the resistive load and the power switch. This application does not limit how the arc extinguishing module is connected to the circuit of the resistive load and the power switch. The specific connection relationship may be as follows but not limited to: Figure 2 As shown, the arc extinguishing module's V in The input voltage terminal is connected to the positive pole of the power supply and the V 0 The output voltage terminal is connected to the relay control board, the GND terminal (ground terminal) of the arc extinguishing module is connected to the heating resistor, and the control terminal of the arc extinguishing module (one port is left in the figure) is connected to the negative pole of the power supply. The function of the arc extinguishing module is to quickly extinguish the arc when the relay is disconnected.

[0063] Figure 3 A schematic diagram of the structure of an arc extinguishing module according to an embodiment of the present application is shown. Figure 3 It can be seen that the arc extinguishing module at least includes: a power conversion circuit, an arc extinguishing circuit, and a main control chip; the arc extinguishing circuit is connected in series to the loop of the resistive load and the power switch; the power conversion circuit is connected in parallel to the two poles of the power switch, and the power conversion circuit is a flyback buck circuit, which is used to draw power from the power bus and convert the electrical energy into specified low-voltage electrical energy to supply the main control chip; the main control chip is electrically connected to the arc extinguishing circuit, and the main control chip is used to drive the arc extinguishing circuit.

[0064] That is, the arc extinguishing module is mainly composed of three parts, namely, the power conversion circuit, the arc extinguishing circuit, and the main control chip, wherein the arc extinguishing circuit is connected in series to the loop of the resistive load and the power switch, and mainly plays the role of arc extinguishing; in some embodiments of the present application, the arc extinguishing circuit includes an IGBT device, and the IGBT device is connected in series in the heating circuit to chop the input voltage, simulate the AC zero-crossing characteristics, and destroy the arc column characteristics, thereby achieving an effective arc extinguishing effect.

[0065] The power conversion circuit is connected in parallel to the two poles of the power switch. The main function of the power conversion circuit is to draw power from the bus and convert the electrical energy into a specified low voltage, such as 12V voltage, to supply the electrical energy to the main control chip. In some embodiments of the present application, a flyback buck circuit is formed by a UC3845 control chip, a high-frequency transformer, a diode, and an RCD absorption circuit to obtain a power conversion circuit, thereby realizing the circuit operation of outputting a low voltage of 12V to the main control chip.

[0066] One of the functions of the main control chip is to drive the arc extinguishing circuit. In some embodiments of the present application, the main control chip is recommended to be, but not limited to, the GD32F103 series control chip.

[0067] Please refer to Figure 3The arc extinguishing module may also include but is not limited to: a bus voltage detection circuit, an external trigger circuit, a communication circuit, a flexible grounding circuit, a sensor circuit, etc. (not shown in the figure). The bus voltage detection circuit, the external trigger circuit, the communication circuit, the flexible grounding circuit, and the sensor circuit are respectively connected to the main control chip; among which, the flexible grounding circuit is used to connect the flexible grounding system, the communication circuit is used to connect the communication system, the sensor circuit is used to connect the temperature sensor, and the bus voltage detection circuit is used to connect the bus voltage detection system, and the external trigger circuit is used to receive an external trigger signal.

[0068] The bus voltage detection circuit, external trigger circuit, communication circuit, flexible grounding circuit, sensor circuit, etc. can be added or reduced as needed and will not be elaborated here.

[0069] For details, please refer to Figure 4 , Figure 4 A schematic diagram of the structure of an arc extinguishing circuit according to an embodiment of the present application is shown. Figure 4 It can be seen that the arc extinguishing circuit includes a first driving branch, a second driving branch and an on-off branch, wherein the first driving branch and the second driving branch are respectively used to amplify the driving signal, perform signal conversion and voltage stabilization protection in sequence, thereby respectively controlling at least part of the on-off branch.

[0070] More specifically, the first driving branch includes: a first resistor (R1), a second resistor (R2), a first optocoupler (OP1), a first NPN transistor (Q1), a first PNP transistor (Q2), a third resistor (R3), a fourth resistor (R4), a first voltage regulator (D1), and a fifth resistor (R5).

[0071] like Figure 4 As shown, one end of the first resistor (R1) is connected to the driving signal (Dirver1), and the other end of the first resistor (R1) is connected to the first pin of the first optical coupler (OP1) and one end of the second resistor (R2). Figure 5 As shown, the pins are defined as follows Figure 5 As shown in, the same below.

[0072] The other end of the second resistor (R2) is connected to the second pin of the first optical coupler (OP1) and is grounded.

[0073] The third pin of the first optical coupler (OP1) is respectively connected to the control end of the first NPN transistor (Q1), the control end (Q2) of the first PNP transistor and one end of the fourth resistor (R4).

[0074] The fourth pin of the first optical coupler (OP1) is connected to the input end of the first NPN transistor (Q1).

[0075] The output end of the first NPN transistor (Q1) is respectively connected to one end of the third resistor (R3) and the input end of the first PNP transistor (Q2).

[0076] The other end of the fourth resistor (R4) is respectively connected to the output end of the first PNP transistor (Q2), the anode of the first voltage regulator (D1) and one end of the fifth resistor (R5) and is connected to the signal ground line (BGND).

[0077] The other end of the third resistor (R3) is respectively connected to the cathode of the first voltage regulator (D1) and the other end of the fifth resistor (R5) and is connected to the on-off branch as the output end of the first driving branch, specifically the second field effect transistor (Q6) in the figure.

[0078] The second driving branch includes: a sixth resistor (R6), a seventh resistor (R7), a second optical coupler (OP2), a second NPN transistor (Q3), a second PNP transistor (Q4), an eighth resistor (R8), a ninth resistor (R9), a second voltage regulator (D2), and a tenth resistor (R10).

[0079] One end of the sixth resistor (R6) is connected to the driving signal (Dirver1), and the other end of the sixth resistor (R6) is respectively connected to the first pin of the second optical coupler (OP2) and one end of the seventh resistor (R7).

[0080] The other end of the seventh resistor (R7) is connected to the second pin of the second optical coupler (OP2) and is grounded.

[0081] The third pin of the second optical coupler (OP2) is respectively connected to the control end of the second NPN transistor (Q3), the control end of the second PNP transistor (Q4) and one end of the ninth resistor (R9).

[0082] The fourth pin of the second optical coupler (OP2) is connected to the input end of the second NPN transistor (Q3).

[0083] The output end of the second NPN transistor (Q3) is respectively connected to one end of the eighth resistor (R8) and the input end of the second PNP transistor (Q4).

[0084] The other end of the ninth resistor (R9) is respectively connected to the output end of the second PNP transistor (Q4), the anode of the second voltage regulator (D2) and one end of the tenth resistor (R10) and is connected to the signal ground line (BGND).

[0085] The other end of the eighth resistor (R8) is respectively connected to the cathode of the second voltage regulator (D2) and the other end of the tenth resistor (R10) and is connected to the on-off branch as the output end of the second driving branch, specifically the first field effect transistor (Q5) in the figure.

[0086] Please refer to Figure 4 The on-off branch includes: two parallel-connected first field effect transistors (Q5) and second field effect transistors (Q6). The first field effect transistor (Q5) is connected to the output end of the second driving branch, i.e., G2 in the figure; the second field effect transistor (Q6) is connected to the output end of the first driving branch, i.e., G1 in the figure;

[0087] The parallel point of the first field effect transistor (Q5) and the second field effect transistor (Q6) is connected in series to the loop of the resistive load and the power switch, that is, as shown in the figure, the Ci terminal and the DCO+ terminal are connected in series to the loop of the resistive load and the power switch respectively.

[0088] In some embodiments of the present application, the first field effect transistor (Q5) and the second field effect transistor (Q6) are CI30N120SM tubes.

[0089] The working principle of the arc extinguishing circuit is as follows: the PWM signal output by the control chip is isolated and amplified to the secondary side through the isolation optical couplers OP1 and OP2. In some embodiments, the driving signal frequency is 50HZ, the rated duty cycle is 70%, and the duty cycle can be flexibly adjusted through the main circuit bus voltage detection, thereby achieving adjustable and controllable heating power. The secondary side adopts a push-pull driving circuit with two tubes in parallel, and the push-pull circuit is composed of Q1 (NPN type), Q2 (PNP type) and Q3 (NPN type), Q4 (PNP type). The main circuit can use CI30N120SM tubes, etc. The peak current of the single tube drain can reach 30A, which increases the conduction current of the heating circuit and reduces the heating of the module. Ci and DCO+ are connected in series in the circuit respectively to achieve the chopping effect, and simulate the AC zero-crossing characteristics when the main circuit power flows through the switch, thereby achieving effective arc extinguishing.

[0090] From the above description, it can be seen that the present application realizes the DC transformation of loads by replacing devices and changing circuits, thereby providing a design scheme for the transformation of heating resistive loads in a zero-carbon power supply station, and providing guarantee for the high-reliability power supply and safe and stable operation of the entire photovoltaic storage direct-flexible system. From the system perspective, the present application brings effective and convenient load absorption to the photovoltaic storage direct-flexible system, which absorbs loads on-site and significantly improves the utilization rate of photovoltaics; the DC application of necessary loads saves energy and reduces electricity costs; the resistive load can flexibly adjust the output power according to the DC bus voltage and calmly face bus fluctuations; and reduces the energy conversion loss in the system. From the perspective of product-level products, the present application replaces the original AC step-down solution and adopts a switching power supply module to reduce the size and noise of the transformer and reduce costs; solves the problem of arcing of DC resistive load switches, avoids the burning and damage caused by arcing, and has the characteristics of high stability and high reliability; reduces the risk of electric shock.

[0091] The above is only a specific implementation of the present application. Under the above teachings of the present application, those skilled in the art can make other improvements or modifications based on the above embodiments. Those skilled in the art should understand that the above specific description is only to better explain the purpose of the present application, and the protection scope of the present application shall be based on the protection scope of the claims.

[0092] In addition, those skilled in the art will appreciate that, although some embodiments described herein include certain features included in other embodiments but not other features, the combination of features of different embodiments is meant to be within the scope of the present application and form different embodiments. For example, in the claims below, any one of the claimed embodiments may be used in any combination.

Claims

1. A resistive load DC circuit, the resistive DC load circuit comprising at least: A power switch, a resistive load and an electrical appliance controller, wherein the electrical appliance controller at least comprises: a relay control board and a solenoid valve; the resistive load is loaded between the two poles of the power switch, and the power switch is also connected to the electrical appliance controller; characterized in that: An arc extinguishing module is added to the circuit of the resistive load and the power switch, and the arc extinguishing module is used to eliminate the arcing phenomenon that occurs when the power switch is turned on and off; The power switch is a high-frequency flyback power switch; The solenoid valve is a DC solenoid valve.

2. The resistive load DC circuit according to claim 1, characterized in that: The arc extinguishing module at least includes: a power conversion circuit, an arc extinguishing circuit, and a main control chip; The arc extinguishing circuit is connected in series to the loop of the resistive load and the power switch; The power conversion circuit is connected in parallel to the two poles of the power switch. The power conversion circuit is a flyback buck circuit, which is used to take power from the power bus and convert the power into a specified low-voltage power to supply to the main control chip; The main control chip is electrically connected to the arc extinguishing circuit, and the main control chip is used to drive the arc extinguishing circuit.

3. The resistive load DC circuit according to claim 2, characterized in that: The arc extinguishing module further includes: a bus voltage detection circuit, an external trigger circuit, a communication circuit, a flexible grounding circuit, and a sensor circuit, wherein the bus voltage detection circuit, the external trigger circuit, the communication circuit, the flexible grounding circuit, and the sensor circuit are respectively connected to the main control chip; Among them, the flexible grounding circuit is used to connect to the flexible grounding system, the communication circuit is used to connect to the communication system, the sensor circuit is used to connect to the temperature sensor, the bus voltage detection circuit is used to connect to the bus voltage detection system, and the external trigger circuit is used to receive an external trigger signal.

4. The resistive load DC circuit according to claim 2, characterized in that: The arc extinguishing circuit comprises a first driving branch, a second driving branch and a switching branch; The first driving branch and the second driving branch are respectively used to amplify, convert and perform voltage stabilization protection on the driving signal in sequence, so as to respectively control at least part of the on-off branch.

5. The resistive load DC circuit according to claim 4, characterized in that: The first driving branch includes: a first resistor, a second resistor, a first optocoupler, a first NPN transistor, a first PNP transistor, a third resistor, a fourth resistor, a first voltage regulator, and a fifth resistor; One end of the first resistor is connected to the driving signal, and the other end of the first resistor is respectively connected to the first pin of the first optical coupler and one end of the second resistor; The other end of the second resistor is connected to the second pin of the first optical coupler and is grounded; The third pin of the first optical coupler is respectively connected to the control end of the first NPN transistor, the control end of the first PNP transistor and one end of the fourth resistor; The fourth pin of the first optical coupler is connected to the input end of the first NPN transistor; The output end of the first NPN transistor is respectively connected to one end of the third resistor and the input end of the first PNP transistor; The other end of the fourth resistor is respectively connected to the output end of the first PNP transistor, the anode of the first voltage regulator tube and one end of the fifth resistor and is connected to the signal ground line; The other end of the third resistor is respectively connected to the cathode of the first voltage regulator tube, and the other end of the fifth resistor is connected to the on-off branch as the output end of the first driving branch.

6. The resistive load DC circuit according to claim 4, characterized in that: The second driving branch includes: a sixth resistor, a seventh resistor, a second optical coupler, a second NPN transistor, a second PNP transistor, an eighth resistor, a ninth resistor, a second voltage regulator, and a tenth resistor; One end of the sixth resistor is connected to the driving signal, and the other end of the sixth resistor is respectively connected to the first pin of the second optical coupler and one end of the seventh resistor; The other end of the seventh resistor is connected to the second pin of the second optical coupler and is grounded; The third pin of the second optical coupler is respectively connected to the control end of the second NPN transistor, the control end of the second PNP transistor and one end of the ninth resistor; The fourth pin of the second optical coupler is connected to the input end of the second NPN transistor; The output end of the second NPN transistor is respectively connected to one end of the eighth resistor and the input end of the second PNP transistor; The other end of the ninth resistor is respectively connected to the output end of the second PNP transistor, the anode of the second voltage regulator tube and one end of the tenth resistor and is connected to the signal ground line; The other end of the eighth resistor is respectively connected to the cathode of the second voltage regulator tube, and the other end of the tenth resistor is connected to the on-off branch as the output end of the second driving branch.

7. The resistive load DC circuit according to claim 4, characterized in that: The on-off branch includes: two first field effect transistors and a second field effect transistor connected in parallel; The first field effect transistor is connected to the output end of the second driving branch; The second field effect transistor is connected to the output end of the first driving branch; A parallel connection point of the first field effect transistor and the second field effect transistor is connected in series to a loop of the resistive load and the power switch.

8. The resistive load DC circuit according to claim 7, characterized in that: The first field effect transistor and the second field effect transistor are CI30N120SM tubes.

9. The resistive load DC circuit according to claim 1, characterized in that: The DC solenoid valve is 24V.

10. Application of the resistive load DC circuit according to any one of claims 1 to 9 in electrical appliance manufacturing.

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