A method for testing and transforming household load direct current power supply

Abstract

The application discloses a kind of domestic load direct current power supply test reforming method, including classifying domestic load;According to load category, direct current technology analysis is carried out, and the range needing to be reformed is determined;Judge whether domestic load can be AC / DC universal, if yes, then direct current power supply test is carried out, and safe working direct current voltage is determined;Otherwise, judge whether direct current reforming can be carried out, if not, then AC power supply is carried out;Otherwise, power-on test is carried out to domestic load, and whether arc is generated is judged, if yes, then arc extinguishing is carried out first, and then direct current reforming is carried out to AC component;Otherwise, direct current reforming is directly carried out to AC component, and stability test is carried out after reforming is completed;Finally, direct current load list is formed.The application provides a kind of scheme for domestic load direct current reforming and improving energy conversion efficiency, has very strong practicability, and simultaneously, provides a kind of direct current arc extinguishing method for arc problem in the process of breaking of direct current load, improves electrical safety.

Description

Technical Field

[0001] This invention relates to DC power supply technology, and in particular to a method for testing and modifying DC power supply for household loads. Background Technology

[0002] Currently, most loads on the market are designed for AC power supply, resulting in a lack of low-voltage DC systems. With the rapid development of power electronics and the increasing application of new energy sources such as photovoltaics and energy storage in the civilian sector, the demand for efficient and localized utilization of new energy sources and seamless connection between loads and new energy sources is becoming increasingly prominent. Meanwhile, most household loads, such as inverter air conditioners, energy-saving refrigerators, computers, and LED lights, use DC power internally or contain DC links, leading to increased energy loss after multiple energy conversions. Researching DC-to-DC conversion of loads can improve energy conversion efficiency, flexibly absorb new energy sources, and promote the development of new energy. Summary of the Invention

[0003] Purpose of the invention: The purpose of this invention is to provide a method for modifying the DC power supply test for household loads.

[0004] Technical solution: The present invention provides a method for testing and modifying the DC power supply of a household load, comprising the following steps:

[0005] S1. Household loads can be classified according to their power supply principle, including: rectifier bridge loads, speed-regulating motor loads, power adapter loads, and resistance heating loads.

[0006] S2. Conduct DC conversion technology analysis according to load type to determine the scope of the modification required;

[0007] S3. Determine whether the household load can use both AC and DC. If so, perform a DC power supply test, comparing the DC voltage from low to high to determine the safe operating DC voltage. If not, proceed to step S4.

[0008] S4. Determine whether the household load can be converted to DC power. If not, then AC power supply is required; if so, proceed to step S5.

[0009] S5. Perform a power-on test on the household load to determine if an electric arc is generated. If so, extinguish the arc first, and then convert the AC components in the household load to DC. Otherwise, directly convert the AC components in the household load to DC. After the conversion is completed, perform a stability test to ensure that the conversion is successful and that the converted load can work normally for a long time.

[0010] S6. Generate a list of DC loads.

[0011] Furthermore, rectifier bridge loads are loads powered by AC220V or AC380V AC power rectified into pulsating DC power by the rectifier bridge.

[0012] Speed-regulating motor loads are driven by frequency converters;

[0013] It is compatible with power supply loads that are powered by an adapter or switching power supply;

[0014] Resistance heating loads are compatible with both AC and DC.

[0015] Furthermore, for rectifier bridge loads, when the input is AC, during the positive half-cycle, the load voltage is positive at the top and negative at the bottom; during the negative half-cycle, the load voltage is also positive at the top and negative at the bottom, exhibiting a "bun wave" waveform. When the input is DC, the diodes act as wires, so regardless of whether the input is AC or DC, the output of the subsequent stage is always DC. Additionally, with a DC input, the voltage value is [missing value] compared to the AC input. The AC range of 150V to 265V corresponds to a DC range of 212V to 375V, so a DC range of 220V meets the operating range requirements.

[0016] Furthermore, for speed-regulating motor loads, there is a rectification-frequency conversion stage, and the average output DC voltage is 515V. With the addition of the filter capacitor C and a light load, the DC output voltage reaches 539V, so a DC 540V power supply is sufficient to meet the requirements.

[0017] Furthermore, for power supply-type loads, the AC is rectified and then converted into ultra-low voltage DC via a DC / DC converter; after a standard 220V AC input adapter, it will be converted to power the auxiliary circuits; thus enabling DC power supply.

[0018] Furthermore, resistance heating loads can be used with both AC and DC power.

[0019] Furthermore, the arc extinguishing method is as follows: a capacitor is connected in parallel with the load to eliminate the voltage difference across the load switch, thereby preventing the generation of an electric arc during the opening and closing of the load switch; at the same time, a semiconductor switch is connected in parallel across the load switch, and a current-limiting resistor is connected in series with the semiconductor switch. Before the load switch is opened, the semiconductor switch is closed first to achieve arc-free insertion and removal throughout the process.

[0020] Furthermore, a timer is used to control the on / off time of the load switch and the semiconductor switch. When the semiconductor switch is closed, the timer starts counting down. After the time is up, the load switch is either driven to close first or open first, and the semiconductor switch opens later.

[0021] Furthermore, the timer duration is set based on the capacitor's full charging time. The formula for calculating the capacitor charging time t is: Where u is the power supply voltage, u cR1 is the capacitor voltage, R2 is the current-limiting resistor, C is the capacitance value, and t is the capacitor charging time.

[0022] Based on the same inventive concept, the present invention provides an electrical appliance DC power supply testing and modification system, comprising:

[0023] The household load classification unit is used to classify household loads according to their power supply principle, including: rectifier bridge loads, speed-regulating motor loads, power adapter loads, and resistance heating loads;

[0024] The DC conversion analysis unit is used to perform DC conversion technology analysis according to load type, thereby determining the scope of modification required;

[0025] The first judgment unit is used to determine whether the household load can use both AC and DC. If so, a DC power supply test is performed, and the DC voltage is compared from low to high to determine the safe operating DC voltage. If not, the second judgment unit is executed.

[0026] The second judgment unit is used to determine whether the household load can be converted to DC power. If not, it will be powered by AC; if so, it will execute the DC conversion unit.

[0027] The DC conversion unit is used to test the power supply of household loads to determine if an electric arc is generated. If so, the arc is extinguished first, and then the AC components in the household load are converted to DC. Otherwise, the AC components in the household load are directly converted to DC. After the conversion is completed, a stability test is performed to ensure that the conversion is successful and that the converted load can work normally for a long time.

[0028] The DC load list generation unit is used to generate a DC load list.

[0029] Beneficial effects: Compared with the prior art, the advantages of the present invention are:

[0030] (1) Classify and study different household loads first, which will provide guidance for the transformation of different types of loads;

[0031] (2) The DC conversion study of typical household loads has strong practical value;

[0032] (3) A DC arc extinguishing method is provided to address the arcing problem of DC loads during the switching process, thereby improving electrical safety;

[0033] (4) A solution is provided for the DC transformation of home appliances to improve energy conversion efficiency. Attached Figure Description

[0034] Figure 1 This is a flowchart of the load DC power supply test modification method of the present invention;

[0035] Figure 2 This is a schematic diagram of a DC arc extinguishing circuit;

[0036] Figure 3 This is the schematic diagram of a 555 timer circuit.

[0037] Figure 4 This is a circuit diagram for an LED light.

[0038] Figure 5 This is the circuit diagram of the dryer. Detailed Implementation

[0039] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0040] like Figure 1 As shown, the present invention provides a method for testing and modifying the DC power supply of a household load, comprising the following steps:

[0041] S1. Household loads can be classified according to their power supply principle, including: rectifier bridge loads, speed-regulating motor loads, power adapter loads, and resistance heating loads.

[0042] S11. Rectifier bridge type loads are AC220V or AC380V AC that is rectified into pulsating DC by a rectifier bridge; typical loads include induction cookers, projectors, televisions, desktop computers, LED lights, etc.

[0043] S12. Speed-regulating motor loads are mostly driven by frequency converters; typical loads include frequency converter air conditioners, frequency converter washing machines, frequency converter refrigerators, range hoods, air purifiers, etc.

[0044] S13. Power supply type loads are mostly powered by adapters or switching power supplies; typical loads include access control power supplies, surveillance cameras, mobile phones, laptops, etc.

[0045] S14. Resistance heating loads are compatible with both AC and DC; typical loads include kettles, water dispensers, and incandescent lamps.

[0046] S2. Conduct DC conversion technology analysis according to load type to determine the scope of the modification required;

[0047] S21. For rectifier bridge loads, when the input is AC, during the positive half-cycle, the load voltage is positive at the top and negative at the bottom; during the negative half-cycle, the load voltage is also positive at the top and negative at the bottom, with a waveform resembling a "bun wave." When the input is DC, the diodes act as wires, so the output of the subsequent stage is always DC regardless of whether the input is AC or DC. Furthermore, with DC input, the voltage value is [missing value] of the AC input. The AC range of 150V to 265V corresponds to a DC range of 212V to 375V, indicating that 220V DC meets the operating range requirements.

[0048] S22. For variable speed motor loads, there is usually a rectification-frequency conversion stage. Taking a central air conditioner as an example, the AC power is rectified by a three-phase rectifier to output pulsating DC. Within one AC cycle, the DC output voltage contains six dome-shaped ripples, with the highest ripple value being 539V and the lowest being 467V. The average output DC voltage is 515V. If a filter capacitor C is added, the DC output voltage can reach 539V under light load (with a larger R value). Therefore, a 540V DC power supply is suitable.

[0049] S23. For power supply-type loads, the AC power is rectified and then converted to ultra-low voltage DC via a DC / DC converter. A standard 220V AC input adapter will perform a conversion to power auxiliary circuits. Taking a 220V to 5V, 12V, 24V step-down circuit as an example, we can see that the DC voltage generated after AC power is rectified by the rectifier bridge can be output as ultra-low voltage DC via a flyback converter circuit, achieving voltage level conversion without an AC transformer. Research using a typical 5V / 500mA non-isolated power supply (commonly used in rice cookers and washing machines) shows that there is no transformer at the end of the rectifier bridge. DC voltage conversion is controlled by the XD308 chip. According to the XD308 chip manual, its input is 18V to 600V DC, and it can output DC 3.3V, 5.0V, 12V, and 24V. Therefore, DC power supply is feasible.

[0050] S24. Resistance heating loads can be used with both AC and DC power, but when using DC power supply, attention should be paid to the problem of arcing during switching.

[0051] S3. Determine whether the household load can use both AC and DC. If so, perform a DC power supply test, comparing the DC voltage from low to high to determine the safe operating DC voltage. If not, proceed to step S4.

[0052] S4. Determine whether the household load can be converted to DC power. If not, then AC power supply is required; if so, proceed to step S5.

[0053] S5. Perform a power-on test on the household load to determine if an electric arc is generated. If so, extinguish the arc first, and then convert the AC components in the household load to DC. Otherwise, directly convert the AC components in the household load to DC. After the conversion is completed, perform a stability test to ensure that the conversion is successful and that the converted load can work normally for a long time.

[0054] like Figure 2As shown, considering the DC blocking characteristic of capacitors, an arc will be generated during the load switch opening process. A capacitor is connected in parallel with the load to eliminate the voltage difference across the switch, thus preventing arcing during the opening process. Simultaneously, considering the sparking problem caused by excessive capacitor charging current at the moment semiconductor switch S1 closes, a current-limiting resistor is connected in series, and semiconductor switch S1 is closed first to achieve arc-free insertion and removal throughout the entire process. According to the formula... Derive the capacitor charging time Calculate the capacitor's full charging time and set a suitable time for the timer. Here, u is the power supply voltage, u... c R1 is the capacitor voltage, R2 is the current-limiting resistor, C is the capacitance of capacitor C1, and t is the capacitor charging time.

[0055] like Figure 3 As shown, the timer uses a 555 timer. When semiconductor switch S1 is closed, the timer starts counting. When the time is up, it sends a low-level signal, which sends a drive signal through a relay or optocoupler to drive S2 to close or open first, and then S1 to open, thereby avoiding the generation of an electric arc.

[0056] In this embodiment of the invention, one load is selected from both AC / DC universal and modifiable household loads for testing and modification. For the AC / DC universal load, an LED light is selected for DC power supply testing. The DC voltage is increased from low to high, and the operating states are compared to determine the DC voltage at which normal operation can be achieved. Figure 4 The diagram shows the circuit schematic for an LED lamp. R7 is a protective resistor, and R8 is the discharge resistor for capacitor C4. The 220V AC power is stepped down by capacitor C4, then rectified by a full-bridge rectifier, filtered by capacitor C5, and finally supplies a constant current to the 40 LEDs connected in series via current-limiting resistor R9. This type is suitable for both AC and DC power supply. For DC power supply testing, an adjustable voltage source is used to supply DC power, and the DC voltage range is adjusted. The observed phenomena are then used to determine the appropriate DC power supply voltage range.

[0057] The dryer can be selected for modification based on the load, the scope of modification needs to be determined, and arc extinguishing design studies should be conducted simultaneously. For example... Figure 5 The diagram shows the circuit schematic of the dryer, which is divided into a DC inverter motor and a heating circuit. The DC inverter motor requires no modification and can be directly connected to DC. The heating circuit is controlled by a relay for power supply and a bidirectional thyristor for circuit switching. Considering the resistive load characteristics, an arc-extinguishing module is connected in series for arc suppression. Testing the modified circuit revealed that the heating was not working. Further investigation showed that the bidirectional thyristor was not conducting after power-on, therefore, it needed modification.

[0058] After the modification, stability testing was conducted to ensure the modification was successful and that the modified load could operate for an extended period of time.

[0059] S6. Finally, a list of DC loads is generated.

[0060] Based on the same inventive concept, the present invention provides a DC power supply testing and modification system for household loads, comprising:

[0061] The household load classification unit is used to classify household loads according to their power supply principle, including: rectifier bridge loads, speed-regulating motor loads, power adapter loads, and resistance heating loads;

[0062] The DC conversion analysis unit is used to perform DC conversion technology analysis according to load type, thereby determining the scope of modification required;

[0063] The first judgment unit is used to determine whether the household load can use both AC and DC. If so, a DC power supply test is performed, and the DC voltage is compared from low to high to determine the safe operating DC voltage. If not, the second judgment unit is executed.

[0064] The second judgment unit is used to determine whether the household load can be converted to DC power. If not, it will be powered by AC; if so, it will execute the DC conversion unit.

[0065] The DC conversion unit is used to test the power supply of household loads to determine whether an electric arc is generated. If so, the arc is extinguished first, and then the AC components in the household load are converted to DC. Otherwise, the AC components in the household load are directly converted to DC. After the conversion is completed, a stability test is performed to ensure that the conversion is successful and that the converted load can work normally for a long time.

[0066] The DC load list generation unit is used to generate a DC load list.

Claims

1. A method for testing and modifying the DC power supply of a household load, characterized in that, Includes the following steps: S1. Household loads can be classified according to their power supply principle, including: rectifier bridge loads, speed-regulating motor loads, adapter power supply loads, and resistance heating loads. Rectifier bridge loads are powered by AC220V or AC380V AC rectified into pulsating DC power by a rectifier bridge. Speed-regulating motor loads are driven by frequency converters. Adapter power supply loads are powered by adapters or switching power supplies. Resistance heating loads are AC / DC compatible. S2. Conduct DC conversion technology analysis according to load type to determine the scope of the modification required; S3. Determine whether the household load can use both AC and DC. If so, perform a DC power supply test, comparing the DC voltage from low to high to determine the safe operating DC voltage. If not, proceed to step S4. S4. Determine whether the household load can be converted to DC power. If not, then AC power supply is required; if so, proceed to step S5. S5. Perform a power-on test on the household load to determine if an electric arc is generated. If so, extinguish the arc first, and then convert the AC components in the household load to DC. Otherwise, directly convert the AC components in the household load to DC. After the conversion is completed, perform a stability test to ensure that the conversion is successful and that the converted load can work normally for a long time. The arc extinguishing method is as follows: a capacitor is connected in parallel with the load to eliminate the voltage difference across the load switch, thereby preventing the generation of electric arc during the opening and closing of the load switch; at the same time, a semiconductor switch is connected in parallel across the load switch, and a current-limiting resistor is connected in series with the semiconductor switch. Before the load switch is opened, the semiconductor switch is closed first to achieve arc-free insertion and removal throughout the process. A timer is used to control the on / off time of the load switch and the semiconductor switch. When the semiconductor switch is closed, the timer starts counting down. When the time is up, the load switch is driven to close or open first, and the semiconductor switch opens later. The timer duration is set based on the capacitor's full charging time. The formula for calculating the capacitor charging time t is: ,in, This is the power supply voltage. The voltage across the capacitor. For current limiting resistor, For load, t represents the capacitance value, and t represents the capacitor charging time. S6. Generate a list of DC loads.

2. The method for testing and modifying DC power supply for household loads according to claim 1, characterized in that: For rectifier bridge loads, when the input is AC, during the positive half-cycle of conduction, the load voltage is positive at the top and negative at the bottom; during the negative half-cycle of conduction, the load voltage is also positive at the top and negative at the bottom, exhibiting a "bun wave" waveform. When the input is DC, the diodes act as wires, therefore, regardless of whether the input is AC or DC, the output of the subsequent stage is always DC. Furthermore, with a DC input, the voltage value is [missing value] compared to the AC input. The AC range of 150V to 265V corresponds to a DC range of 212V to 375V, so a DC range of 220V meets the operating range requirements.

3. The method for testing and modifying the DC power supply of a household load according to claim 1, characterized in that: For speed-regulating motor loads, there is a rectification-frequency conversion stage. The average output DC voltage is 515V. With the addition of filter capacitor C and light load, the DC output voltage reaches 539V. Therefore, a DC 540V power supply is sufficient to meet the requirements.

4. The method for testing and modifying the DC power supply of a household load according to claim 1, characterized in that: For power supply type loads, the AC is rectified and then converted into ultra-low voltage DC through DC / DC converter; After a standard 220V AC input adapter, a conversion is performed to power the auxiliary circuitry; thus enabling DC power supply.

5. The method for testing and modifying the DC power supply of a household load according to claim 1, characterized in that: Resistance heating loads can be used with both AC and DC power.

6. An electrical appliance DC power supply testing and modification system, characterized in that, This system is used in the household load DC power supply test modification method according to any one of claims 1-5, and the system includes: The household load classification unit is used to classify household loads according to their power supply principle, including: rectifier bridge loads, speed control motor loads, power adapter loads, and resistance heating loads; The DC conversion analysis unit is used to perform DC conversion technology analysis according to load type, thereby determining the scope of modification required; The first judgment unit is used to determine whether the household load can use both AC and DC. If so, a DC power supply test is performed, and the DC voltage is compared from low to high to determine the safe operating DC voltage. If not, the second judgment unit is executed. The second judgment unit is used to determine whether the household load can be converted to DC power. If not, it will be powered by AC; if so, it will execute the DC conversion unit. The DC conversion unit is used to test the power supply of household loads to determine if an electric arc is generated. If so, the arc is extinguished first, and then the AC components in the household load are converted to DC. Otherwise, the AC components in the household load are directly converted to DC. After the conversion is completed, a stability test is performed to ensure that the conversion is successful and that the converted load can work normally for a long time. The DC load list generation unit is used to generate a DC load list.

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