A power supply control circuit for a heat pump water heater

Abstract

The utility model relates to a kind of heat pump water heater power supply control circuit, belong to heat pump control technical field.Through respectively adopting commercial power rectification, PFC and boost module and photovoltaic drive and photovoltaic boost module, so that two power supply can be adjusted to the required voltage of DC bus synchronously.In addition, by measuring output voltage and adjusting the proportion of output voltage and open-circuit voltage, efficient cooperation and stable power supply between power supply are realized, and then power supply for compressor using photovoltaic is realized.

Description

Technical Field

[0001] This utility model belongs to the technical field of heat pump systems, and specifically relates to a power supply control circuit for a heat pump water heater. Background Technology

[0002] In the context of green and low-carbon development, photovoltaics is a renewable energy supply solution. However, photovoltaics has a cyclical nature, and if only photovoltaics are used to power heat pump water heaters, they cannot operate stably. Utility Model Content

[0003] To at least solve one of the aforementioned problems in the prior art, this utility model provides a power supply control circuit for a heat pump water heater.

[0004] The objective of this utility model can be achieved through the following technical solutions: A power supply control circuit for a heat pump water heater, comprising: A photovoltaic module, comprising a photovoltaic drive module and a photovoltaic boost module, wherein the photovoltaic drive module is connected to the solar module via a photovoltaic input terminal, and the photovoltaic drive module is connected to the photovoltaic boost module; The mains power module includes a rectifier module and a PFC boost circuit. One end of the rectifier module is connected to the mains power through the mains power input terminal, and the other end of the rectifier module is connected to the PFC boost circuit. Both the PFC boost circuit and the photovoltaic boost module are connected to the DC bus, the DC bus is connected to a frequency converter board, and the frequency converter board is connected to a compressor.

[0005] In a further embodiment of this utility model, the photovoltaic module includes a photovoltaic direct drive board, which is connected to the BUSOUT+ terminal and the BUSOUT- terminal. The PFC boost circuit is also connected to the BUSOUT+ terminal and the BUSOUT- terminal. The BUSOUT+ terminal and the BUSOUT- terminal are respectively connected to the DC bus.

[0006] In a further embodiment of this utility model, the photovoltaic module also includes a main control chip U6, and BUSOUT+ is connected to the second pin of the main control chip U6 through several resistors.

[0007] In a further embodiment of this utility model, the solar module is connected through a positive terminal PV+ and a negative terminal PV-, wherein the positive terminal PV+ is connected to the terminal PV++ after passing through a fuse device, and the terminal PV++ is connected to the third pin (U6-3) of the main control chip U6 after passing through several resistors.

[0008] In a further embodiment of this utility model, a gate driving module is also included. The main control chip U6 sends a PWM signal to the gate driving module, and the gate driving module controls the photovoltaic boost module to boost the voltage according to the received PWM signal.

[0009] In a further embodiment of this invention, the gate module includes a control chip U4. Pin 19 of the main control chip U6 outputs an OUT1 signal, and pin 21 of the main control chip U6 outputs a na48 signal. The OUT1 signal is sent to the ANODE pin of the U4 chip in the gate drive module. The na48 signal is sent to one end of a resistor R84. The other end of the resistor R84 is connected to the base of an NPN transistor Q5. The emitter of transistor Q5 is grounded, and the collector of transistor Q5 is connected to the CATHODE pin of the U4 chip. Based on the received OUT1 and na48 signals, the U4 chip outputs an OUT signal at its VO pin to the photovoltaic boost module.

[0010] In a further embodiment of this utility model, the photovoltaic boost module includes an IGBT boost circuit.

[0011] In a further embodiment of this utility model, the IGBT boost circuit includes a rectifier, one end of the rectifier D1 is connected to a BUS terminal, the other end of the rectifier D1 is connected to a BUSOUT+ terminal, the BUS terminal is also connected to the collector of the IGBT (Q7), the emitter of the IGBT (Q7) is grounded, and the OUT signal is transmitted to the gate of the IGBT (Q7) after passing through a resistor and an optocoupler.

[0012] In a further embodiment of this utility model, the other end of the BUS terminal is also connected to a capacitor (C14), and the capacitor (C14) is grounded through a resistor (R56).

[0013] In a further embodiment of the present invention, the IGBT boost circuit further includes an IGBT (Q7), the BUS terminal is also connected to the collector of the IGBT (Q4), the emitter of the IGBT (Q4) is grounded, and the OUT signal is transmitted to the gate of the IGBT (Q4) after passing through a resistor and an optocoupler.

[0014] This utility model has at least the following beneficial effects: 1. By employing mains rectification, PFC and boost modules, as well as photovoltaic drive and photovoltaic boost modules, photovoltaic power can be effectively utilized and mains power can be used as a supplement when photovoltaic power is unstable. Dual power redundancy ensures that mains power can supplement power supply when photovoltaic power supply is insufficient, ensuring continuous operation of the water heater and improving system reliability.

[0015] 2. By using dynamic voltage tracking and maximum power point tracking technologies, the photovoltaic output voltage is always kept at the optimal power point, achieving efficient coordination and stable power supply between power sources. Attached Figure Description

[0016] To facilitate understanding by those skilled in the art, the present invention will be further described below with reference to the accompanying drawings.

[0017] Figure 1 This is a schematic diagram of the power supply module structure provided in one embodiment of the present invention; Figure 2 This is a partial circuit diagram of the gate drive module provided in one embodiment of the present invention; Figure 3 This is a circuit diagram of the photovoltaic input terminal of the power supply module provided in one embodiment of the present invention; Figure 4 This is a diagram of the IBGT boost circuit in one embodiment of the present invention; Figure 5 This is a schematic diagram showing the connection of the main control chip U6 in some embodiments of the present invention; Figure 6 This is a wiring diagram of the photovoltaic module portion in some embodiments of this utility model; Figure 7 This is a schematic diagram of the input voltage measurement circuit in some embodiments of this utility model; Figure 8 This is a schematic diagram of the connection circuit between the input voltage and the IBGT boost circuit in some embodiments of this utility model; Figure 9 yes Figure 5 A schematic diagram of the pin connections for some pins of the main control chip U6; Figure 10 yes Figure 5 A schematic diagram of the pin connections for the main control chip U6. Detailed Implementation

[0018] To further illustrate the technical means and effects adopted by this utility model in order to achieve the intended utility model purpose, the following detailed description of the specific implementation methods, structure, features and effects of this utility model is provided in conjunction with the accompanying drawings and preferred embodiments.

[0019] In some embodiments, reference Figure 1The power supply control circuit for this heat pump water heater includes a photovoltaic module and a mains power module. The photovoltaic module includes a photovoltaic drive module and a photovoltaic boost module. The photovoltaic drive module is connected to the solar module via a photovoltaic input terminal, and the photovoltaic drive module is connected to the photovoltaic boost module. The mains power module includes a rectifier module and a PFC boost circuit. One end of the rectifier module is connected to the mains power via the mains input terminal, and the other end of the rectifier module is connected to the PFC boost circuit. Both the PFC boost circuit and the photovoltaic boost module are connected to a DC bus. The DC bus is connected to a frequency converter board, and the frequency converter board is connected to a compressor.

[0020] Understandable, Figure 1 The PFC boost circuit in the module can either not operate, allowing the AC mains power to be directly supplied to the DC bus without being boosted, or it can boost the AC mains power. Similarly, the photovoltaic boost module can either boost the voltage input to the solar module or not.

[0021] In some embodiments, the photovoltaic module includes a photovoltaic direct drive board connected to BUSOUT+ and BUSOUT- terminals, and a PFC boost circuit also connected to BUSOUT+ and BUSOUT- terminals. The BUSOUT+ and BUSOUT- terminals are respectively connected to a DC bus. It is understood that the entire photovoltaic module or a portion thereof can be mounted on the photovoltaic drive board; for example, all or part of the photovoltaic drive module and / or photovoltaic boost module can be mounted on the photovoltaic drive board.

[0022] In some embodiments, the photovoltaic drive module further includes a main control chip U6, and BUSOUT+ is connected to the second pin U6-2 of the main control chip U6 through several resistors.

[0023] In some embodiments, the solar module is connected via the positive terminal PV+ and the negative terminal PV-, wherein the positive terminal PV+ is connected to the terminal PV++ after passing through a fuse device, and the terminal PV++ is connected to the third pin U6-3 of the main control chip U6 after passing through several resistors.

[0024] In some embodiments, the photovoltaic drive module includes a gate drive module, and the main control chip U6 sends a PWM signal to the gate drive module, which then controls the photovoltaic boost module to boost the voltage according to the received PWM signal.

[0025] In some implementations, the gate module includes a control chip U4. Pin 19 of the main control chip U6 outputs the OUT1 signal, and pin 21 of the main control chip U6 outputs the na48 signal. The OUT1 signal is sent to the ANODE pin of the U4 chip in the gate drive module. The na48 signal is sent to one end of a resistor R84, the other end of which is connected to the base of an NPN transistor Q5. The emitter of transistor Q5 is grounded, and the collector of transistor Q5 is connected to the CATHODE pin of the U4 chip. Based on the received OUT1 and na48 signals, the U4 chip outputs an OUT signal at its VO pin to the photovoltaic boost module.

[0026] In some embodiments, the photovoltaic boost module includes an IGBT boost circuit.

[0027] In some embodiments, the IGBT boost circuit includes a rectifier, one end of which is connected to a BUS terminal and the other end of which is connected to a BUSOUT+ terminal. The BUS terminal is also connected to the collector of the IGBT-Q7. The emitter of the IGBT-Q7 is grounded, and the OUT signal is transmitted to the gate of the IGBT-Q7 after passing through a resistor and an optocoupler.

[0028] In some embodiments, the other end of the BUS terminal is also connected to a capacitor C14, which is grounded through a resistor R56.

[0029] In some embodiments, the IGBT boost circuit further includes IGBT-Q7, the BUS terminal is also connected to the collector of IGBT-Q4, the emitter of IGBT-Q4 is grounded, and the OUT signal is transmitted to the gate of IGBT-Q4 after passing through a resistor and an optocoupler.

[0030] For details, see Figure 6 The terminals of the solar module after passing through the photovoltaic direct drive panel are BUSOUT+ and BUSOUT-. After the inverter controller is connected to the live and neutral wires, it is connected to the rectifier module and the PFC boost circuit. The two-phase lines from the PFC boost circuit are connected to BUSOUT+ and BUSOUT- respectively, and then connected to the inverter board through the DC bus to control the compressor. Therefore, the voltage at BUSOUT+ is the DC bus voltage.

[0031] Further, see Figure 6The photovoltaic module also includes a main control chip U6. BUSOUT+ is connected to pin 2 of the main control chip U6 via several resistors, thus transmitting the voltage signal at BUSOUT+ to pin 2 of U6. The main control chip U6 can determine whether the compressor is working based on the voltage measured at BUSOUT+ at pin 2. Specifically, when the compressor is not working, the PFC boost circuit is not working, and the voltage measured at BUSOUT+ is the standby voltage. If the compressor is working, the PFC boost circuit will boost the mains voltage, so the voltage at BUSOUT+ is the operating voltage. It is understood that the standby voltage is lower than the operating voltage, and the standby voltage and operating voltage can be a specific value or a range of values.

[0032] Further, see Figure 3 The solar module is connected via a positive electrode PV+ and a negative electrode PV-, with the positive electrode PV+ connected to the PV++ terminal via a fuse. See also Figure 7 PV++ is connected to pin 3 (U6-3) of the main control chip U6 through several resistors. The voltage at PV++ is the input voltage of the photovoltaic module. If the photovoltaic module is open-circuited at this time, the input voltage is the open-circuit voltage of the photovoltaic module.

[0033] Further, see Figure 5 The main control chip U6 sends out the OUT1 signal from pin 19 and the na48 signal from pin 21. The main control chip U6 implements PWM control through the OUT1 and na48 signals.

[0034] In some embodiments, the photovoltaic module further includes a gate drive module. See also... Figure 2 The OUT1 signal is sent to the ANODE pin of the U4 chip in the gate drive module, and the na48 signal is sent to one end of resistor R84. The other end of R84 is connected to the base of an NPN transistor Q5. The emitter of transistor Q5 is grounded, and its collector is connected to the CATHODE pin of the U4 chip. Based on the received OUT1 and na48 signals, the U4 chip outputs the OUT signal at the VO pin to the IGBT boost circuit.

[0035] Further, see Figure 8 PV++ is connected to the BUS via inductor L1. In some embodiments, the photovoltaic module also includes an IGBT boost circuit. See also Figure 4One end of the BUS is connected to one end of rectifier D1, and the other end of rectifier D1 is connected to BUSOUT+. The other end of the BUS is connected to the collector of an IGBT-Q7, and the emitter of Q7 is grounded. The OUT signal is transmitted to the gate of Q7 after passing through a resistor and an optocoupler. A capacitor C14 is also connected to the other end of the BUS, and capacitor C14 is grounded through resistor R56. The BUS can be a terminal block or any other possible circuit structure.

[0036] It is understandable that, in some embodiments, to improve the boost effect, the two IGBTs can be connected to the BUS separately, as shown in the reference. Figure 4 The two IGBTs, Q4 and Q7, are connected to the BUS respectively, and their other circuit connections are basically the same. However, not all situations require two IGBTs; in many cases, a single IGBT is sufficient to achieve a good boost effect.

[0037] During operation, the main control chip U6 determines whether BUSOUT+ is the operating voltage or the standby voltage by detecting the BUSOUT+ voltage value on pin 2.

[0038] If the detected BUSOUT+ voltage value is the standby voltage, it indicates that the compressor is not working at this time. In this case, the main control chip U6 controls the OUT1 and na48 signals to prevent voltage boosting, and obtains the PV++ voltage through pin 3 and records it as the open-circuit voltage.

[0039] When the compressor starts working, the PFC boost circuit begins to boost the voltage. After the main control chip U6 detects that BUSOUT+ is the operating voltage via pin 2, it outputs a PWM control signal to the gate drive module via the OUT1 and na48 signals. The gate drive module then outputs an OUT signal to the IGBT boost circuit accordingly. The IGBT boost circuit boosts the voltage by switching the IGBT on and off and by storing and releasing energy using inductor L1 and capacitor C14. Simultaneously, the main control chip U6 continuously monitors the voltage at PV++ (i.e., the input voltage) via pin 3 and continuously adjusts the PWM signals (OUT1 and na48) based on the input voltage, ensuring that the input voltage is 0.84 times the open-circuit voltage, thereby maximizing the output power of the photovoltaic drive module.

[0040] Please refer to Figure 1In one embodiment, this utility model provides a power supply method for a heat pump water heater with a photovoltaic direct-drive compressor. The power supply module for powering the compressor includes a mains power module, a photovoltaic module, and a DC bus. The mains power module includes a mains power input terminal, which is connected to the DC bus through a rectifier module and a PFC boost module. The photovoltaic module includes a photovoltaic input terminal, which is connected to the DC bus through a photovoltaic drive module and a photovoltaic boost module. The DC bus is connected to the compressor through a frequency converter board. The power supply method includes the following steps: Step S100: Detect and record the open-circuit voltage of the photovoltaic module, and then start the compressor; Step S101: Mains power boost, the mains power is adjusted to the working voltage by the PFC boost module; Step S102: Photovoltaic boost, the photovoltaic power supply provides power to the compressor through the photovoltaic boost module; Step S103: Detect the input voltage of the photovoltaic module, and adjust the power supply ratio of mains power supply and photovoltaic power supply accordingly based on the input voltage and the open circuit voltage.

[0041] In this embodiment, efficient coordinated control of multiple power supplies is achieved by simultaneously connecting both mains power and photovoltaic power to the DC bus. On the mains side, the AC input power is converted into stable DC power through a rectifier module, a PFC module, and a boost module, ensuring that the output voltage matches the DC bus. At the same time, on the photovoltaic side, the DC power output from the solar panel is boosted to the required voltage using a photovoltaic drive module and a photovoltaic boost module, and dynamically follows the voltage changes of the DC bus in real time.

[0042] This solution effectively solves the voltage mismatch problem caused by different power source characteristics and ensures that the photovoltaic output is always in optimal operating condition through maximum power point tracking technology, thereby significantly improving the overall energy utilization efficiency of the system. This design not only enhances the stability of the power supply system but also improves the reliability of energy conversion and utilization, meeting the technical requirements for parallel power supply from multiple power sources.

[0043] In some embodiments, when the photovoltaic voltage is ≥425V, the photovoltaic panel is turned off, and the indicator light flashes twice. When the photovoltaic voltage is ≤415V, normal operation resumes. When the input power is ≥3500W, the input power is limited; when the input power is ≥3600W, the input power is reduced; when the input power is ≥3800W, the photovoltaic panel is turned off, and it automatically resumes normal operation after 60 seconds. When the photovoltaic current is ≥13A, the input power is limited; when the photovoltaic current is ≥14A, the input power is reduced; when the photovoltaic current is ≥16A, the photovoltaic panel is turned off, and it automatically resumes normal operation after 60 seconds. In case of temperature sensor failure, the photovoltaic panel is turned off; when the temperature is ≥80℃, the input power is limited; when the temperature is ≥82℃, the input power is reduced; when the temperature is ≥85℃, the photovoltaic panel is turned off, and it automatically resumes normal operation after 60 seconds.

[0044] In a further embodiment of this utility model, in step S100, after the heat pump water heater is powered on, when the compressor is not running, the mains power drive module boosts the voltage at the DC bus to the standby voltage through PFC boost.

[0045] In some embodiments, after the heat pump water heater is powered on, when the compressor is not running, the mains drive module boosts the voltage at the DC bus to the standby voltage of DC 360V through PFC boost; when the compressor starts running, the mains drive module boosts the voltage at the DC bus to the operating voltage of DC 380V through PFC boost; at the same time, during the operation of the compressor, the power supply voltage is dynamically adjusted according to the different operating frequency requirements of the compressor.

[0046] In a further embodiment of this utility model, step S102 includes: after the compressor starts and the mains drive module raises the voltage at the DC bus to the working voltage, the IGBT switch is controlled by the PWM signal to raise the input voltage of the photovoltaic module to the DC bus, so as to supply power to the compressor together with the mains power.

[0047] In this embodiment, after the compressor starts and the mains drive module boosts the voltage at the DC bus to the operating voltage, the photovoltaic drive module controls the IGBT switch via a PWM signal to boost the input voltage of the solar panel to the DC bus, thus powering the compressor along with the mains power. However, at any given time, only either mains power or photovoltaic power can supply power to the compressor. The power supply module controls the mains power and photovoltaic power to alternately supply power to the compressor via a PWM signal. Furthermore, the power supply module can adjust the ratio of mains power to photovoltaic power supply to the compressor by changing the duty cycle of the PWM signal.

[0048] In a further embodiment of this invention, step S103 includes: stabilizing the input voltage of the photovoltaic module at the maximum power point voltage. When the input voltage of the photovoltaic module is lower than the maximum power point voltage, reducing the PWM duty cycle allows the input voltage to rise back to the maximum power point voltage, allowing the photovoltaic module to operate at maximum power. When the input voltage of the photovoltaic module is near the maximum power point voltage, the PWM duty cycle remains unchanged, allowing the photovoltaic module to operate at maximum power. When the input voltage of the photovoltaic module is higher than the maximum power point voltage, indicating strong sunlight, increasing the PWM duty cycle allows the output voltage to exceed the PFC output value, thereby ensuring that the entire power supply is from the photovoltaic system.

[0049] As the load of photovoltaic power generation becomes heavier, the input voltage of the solar panel will be pulled lower and lower. When the input voltage of the solar panel is at the maximum power point voltage, its output power is at its maximum.

[0050] The maximum power point voltage (MPPT) of the solar panel is used as a setpoint. By comparing the real-time input voltage with the MPPT, the IGBT's on / off state is directly controlled. When the photovoltaic module's input voltage is lower than the MPPT, the PWM duty cycle is reduced to allow the input voltage to rise back to the MPPT, enabling the photovoltaic module to operate at maximum power. When the photovoltaic module's input voltage is near the MPPT, the PWM duty cycle remains constant, allowing the photovoltaic module to operate at maximum power. When the photovoltaic module's input voltage is higher than the MPPT, indicating strong sunlight, the PWM duty cycle is increased to make the output voltage higher than the corresponding PFC output value, thus ensuring that the entire power supply is from the photovoltaic system.

[0051] The open-circuit voltage of the solar panel is a crucial parameter for maximum power point tracking (MPPT). Traditional systems only begin detecting the open-circuit voltage after the compressor starts, resulting in a delay in MPPT response. This embodiment measures the open-circuit voltage of the solar panel during the initial power-up phase (before the compressor starts), providing a reference value for subsequent MPPT.

[0052] In a further embodiment of this invention, the maximum power point voltage is 0.84 times the open-circuit voltage of the solar panel.

[0053] In some embodiments, when the compressor stops while the water heater system is not powered off, the photovoltaic drive module re-detects the open-circuit voltage of the solar panel to prevent sudden changes in illumination from causing the initial value to deviate from the true value during maximum power point tracking.

[0054] In a further embodiment of this invention, the on / off state of the IGBT is controlled by a gate drive module.

[0055] Please refer to Figure 2-5 In this embodiment, the main control chip of the power supply module controls the IGBT boost circuit through the gate driver chip U4. The main control chip of the power supply module is also connected to the gate driver chip U4 through a transistor Q5. The transistor Q5 is an NPN transistor. The base of the transistor Q5 is connected to the main control chip of the power supply module, the collector of the transistor Q5 is connected to the low-level active pin of the gate driver chip, and the emitter of the transistor Q5 is connected to the power supply ground. The main control chip U6 of the power supply module controls the connection and cutoff of the transistor Q5 through the output point signal, thereby controlling whether the low-level active pin of the gate driver chip is grounded, thus realizing the control of the IGBT circuit.

[0056] In a further embodiment of this utility model, step S103 includes: real-time monitoring of DC bus voltage changes, using PWM signals to control alternating power supply from mains power and photovoltaic power to supply power to the compressor, and dynamically adjusting the ratio of mains power supply to photovoltaic power supply by adjusting the duty cycle of the PWM signal to achieve follow-up control of photovoltaic output voltage.

[0057] In a further embodiment of this utility model, when the DC bus voltage is lower than the voltage required for the compressor to operate, the proportion of mains power supply is increased until the DC bus voltage is equal to the voltage required for the compressor to operate; when the DC bus voltage is higher than or equal to the voltage required for the compressor to operate, the proportion of photovoltaic power supply is increased.

[0058] In some embodiments, the power supply module controls the power supply ratio between mains power and photovoltaic power through a PWM signal. When the output voltage at the photovoltaic panel decreases due to insufficient sunlight, the power supply module adjusts the duty cycle of the PWM signal to increase the power supply ratio of mains power in order to maintain the voltage at the DC bus to meet the operating requirements of the compressor. When the output voltage at the photovoltaic panel increases, the power supply module adjusts the duty cycle of the PWM signal to increase the power supply ratio of photovoltaic power in order to reduce the compressor's consumption of mains power.

[0059] The system dynamically adjusts between photovoltaic power supply and mains power supply to ensure the compressor continues to operate normally when the photovoltaic power supply voltage is low. At the same time, it maximizes the proportion of photovoltaic power supply while ensuring the compressor's normal operation, thereby improving the system's utilization rate of environmentally friendly energy.

[0060] In some embodiments, detecting and recording the open-circuit voltage of the photovoltaic module in step S100 includes: The voltage at the DC bus is detected and it is determined whether it is the standby voltage. If the voltage at the DC bus is the standby voltage, the input voltage of the photovoltaic module is detected and recorded as the open circuit voltage.

[0061] In some embodiments, a solar module is connected to the photovoltaic input terminal, and the photovoltaic module includes a photovoltaic direct drive panel.

[0062] In some embodiments, the main control chip U6 can periodically output PWM signals to keep the photovoltaic module in an open-circuit state, while simultaneously measuring and recording the open-circuit voltage of the photovoltaic module.

[0063] The above description is merely a preferred embodiment of the present utility model and is not intended to limit the present utility model in any way. Although the present utility model has been disclosed above with reference to a preferred embodiment, it is not intended to limit the present utility model. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present utility model. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present utility model without departing from the scope of the present utility model shall still fall within the scope of the present utility model.

Claims

1. A power supply control circuit for a heat pump water heater, characterized in that, include: A photovoltaic module, comprising a photovoltaic drive module and a photovoltaic boost module, wherein the photovoltaic drive module is connected to the solar module via a photovoltaic input terminal, and the photovoltaic drive module is connected to the photovoltaic boost module; The mains power module includes a rectifier module and a PFC boost circuit. One end of the rectifier module is connected to the mains power through the mains power input terminal, and the other end of the rectifier module is connected to the PFC boost circuit. Both the PFC boost circuit and the photovoltaic boost module are connected to the DC bus, the DC bus is connected to a frequency converter board, and the frequency converter board is connected to a compressor.

2. The power supply control circuit for a heat pump water heater according to claim 1, characterized in that, The photovoltaic module includes a photovoltaic direct drive board, which is connected to the BUSOUT+ terminal and the BUSOUT- terminal. The PFC boost circuit is also connected to the BUSOUT+ terminal and the BUSOUT- terminal. The BUSOUT+ terminal and the BUSOUT- terminal are respectively connected to the DC bus.

3. The power supply control circuit for a heat pump water heater according to claim 1, characterized in that, The photovoltaic module also includes a main control chip U6, and BUSOUT+ is connected to the second pin of the main control chip U6 through several resistors.

4. The power supply control circuit for a heat pump water heater according to claim 3, characterized in that, The solar module is connected via a positive terminal PV+ and a negative terminal PV-. The positive terminal PV+ is connected to the terminal PV++ after passing through a fuse device. The terminal PV++ is connected to the third pin (U6-3) of the main control chip U6 after passing through several resistors.

5. The power supply control circuit for a heat pump water heater according to claim 3, characterized in that, It also includes a gate drive module, wherein the main control chip U6 sends a PWM signal to the gate drive module, and the gate drive module controls the photovoltaic boost module to boost the voltage according to the received PWM signal.

6. The power supply control circuit for a heat pump water heater according to claim 5, characterized in that, The gate module includes a control chip U4. The OUT1 signal is emitted from pin 19 of the main control chip U6, and the na48 signal is emitted from pin 21 of the main control chip U6. The OUT1 signal is sent to the ANODE pin of the U4 chip of the gate drive module, and the na48 signal is sent to one end of the resistor R84. The other end of the resistor R84 is connected to the base of an NPN transistor Q5. The emitter of the transistor Q5 is grounded, and the collector of the transistor Q5 is connected to the CATHODE pin of the U4 chip. The U4 chip outputs an OUT signal to the photovoltaic boost module at the VO pin according to the received OUT1 and na48 signals.

7. The power supply control circuit for a heat pump water heater according to claim 5, characterized in that, The photovoltaic boost module includes an IGBT boost circuit.

8. The power supply control circuit for a heat pump water heater according to claim 7, characterized in that, The IGBT boost circuit includes a rectifier. One end of the rectifier D1 is connected to a BUS terminal, and the other end of the rectifier D1 is connected to a BUSOUT+ terminal. The BUS terminal is also connected to the collector of the IGBT (Q7). The emitter of the IGBT (Q7) is grounded. The OUT signal is transmitted to the gate of the IGBT (Q7) after passing through a resistor and an optocoupler.

9. The power supply control circuit for a heat pump water heater according to claim 8, characterized in that, The other end of the BUS terminal is also connected to a capacitor (C14), which is grounded through a resistor (R56).

10. A power supply control circuit for a heat pump water heater according to claim 8, characterized in that, The IGBT boost circuit also includes an IGBT (Q7), the BUS terminal is also connected to the collector of the IGBT (Q4), the emitter of the IGBT (Q4) is grounded, and the OUT signal is transmitted to the gate of the IGBT (Q4) after passing through a resistor and an optocoupler.

Images