Control device of photovoltaic water pump and photovoltaic water pump

Abstract

The invention discloses a photovoltaic pump control device and a photovoltaic pump, and relates to the photovoltaic field, the photovoltaic pump control device comprises a photovoltaic module, the output end of the photovoltaic module is connected with the direct current input end of a frequency converter, and the photovoltaic module is used for converting solar energy into direct current and outputting the direct current to the frequency converter; the input end of the AC module is connected with commercial power, and the output end is connected with the AC input end of the frequency converter for outputting the commercial power to the frequency converter; the frequency converter is used for converting the direct current output by the photovoltaic module or the alternating current output by the alternating current module into target alternating current so as to drive the motor; the power supply end of the motor is connected with the output end of the frequency converter, and the output end is connected with the driving end of the water pump. The alternating current module can also supply power to the frequency converter, so that unstable power supply voltage caused by single photovoltaic module power supply is avoided, the frequency converter can convert voltage based on direct current and alternating current, the voltage for driving the water pump is more stable, and meanwhile, the usable time of the photovoltaic water pump is prolonged.

Description

Technical Field

[0001] The present invention relates to the field of photovoltaics, and in particular to a control device for a photovoltaic water pump and a photovoltaic water pump. Background Art

[0002] With the development of the photovoltaic industry, the price of photovoltaic panels has continued to decline, and solar energy resources in remote areas have become more and more cost-effective. Users in remote areas often use photovoltaic panels to generate electricity, and the electricity generated by photovoltaic panels drives water pumps to meet water supply needs. At the same time, photovoltaic panels are more energy-efficient. However, due to poor grid conditions, grid connection difficulties, and high energy storage costs in remote areas, the stability of photovoltaic power generation is relatively low. In actual application scenarios, users may use unstable power grids, which cannot provide stable power supply to water pumps, and the power supply time is short, making it impossible to achieve 24-hour water supply applications. Therefore, it is an urgent problem to provide stable voltage power supply to water pumps. Summary of the invention

[0003] The purpose of the present invention is to provide a control device for a photovoltaic water pump and a photovoltaic water pump. The AC module can also power the inverter, thereby avoiding the unstable power supply voltage caused by the power supply of a single photovoltaic module. The inverter can convert voltage based on direct current and alternating current, and the voltage driving the water pump is more stable, while also increasing the service life of the photovoltaic water pump.

[0004] In order to solve the above technical problems, the present invention provides a control device for a photovoltaic water pump, comprising:

[0005] A photovoltaic module, wherein the output end of the photovoltaic module is connected to the DC input end of the inverter, and is used to convert solar energy into DC power and then output it to the inverter;

[0006] An AC module, the input end of which is connected to the mains, and the output end of which is connected to the AC input end of the frequency converter, for outputting the mains to the frequency converter;

[0007] The frequency converter is used to convert the direct current output by the photovoltaic module or the alternating current output by the alternating current module into target alternating current to drive the motor;

[0008] The motor, wherein the power supply end of the motor is connected to the output end of the frequency converter, and the output end is connected to the driving end of the water pump, is used to drive the water pump.

[0009] On the other hand, the photovoltaic module includes a photovoltaic panel array, a rectifier bridge, a DC circuit breaker and a voltage conversion module;

[0010] The output end of the photovoltaic panel array is connected to the first end of the DC circuit breaker, the second end of the DC circuit breaker is respectively connected to the input end of the voltage converter and the input end of the rectifier bridge, the second end of the rectifier bridge is connected to the DC input end of the inverter, and the output end of the voltage conversion module is connected to the first analog interface of the inverter;

[0011] The photovoltaic panel array is used to convert solar energy into electrical energy, the rectifier bridge is used for rectification, the DC circuit breaker is used to input the electrical energy output by the photovoltaic panel array into the inverter when closed, and the voltage conversion module is used to detect the voltage output by the photovoltaic panel array and feed it back to the inverter.

[0012] On the other hand, the AC module includes an AC circuit breaker, an AC contactor and auxiliary contacts;

[0013] The first end of the AC circuit breaker is connected to the mains, the second end of the AC circuit breaker is connected to the first end of the AC contactor, the second end of the AC contactor is connected to the AC input end of the frequency converter, the control end of the AC contactor is connected to the first control output end of the frequency converter, the first end of the auxiliary contact is connected to the feedback end of the AC contactor, and the second end of the auxiliary contact is connected to the first switch value interface of the frequency converter;

[0014] The AC contactor is used to connect AC power to the frequency converter when it is turned on, and the auxiliary contact is used to determine the connection state of the AC contactor and feed it back to the frequency converter.

[0015] On the other hand, converting the direct current output by the photovoltaic module or the alternating current output by the alternating current module into target alternating current to drive a motor includes:

[0016] When there is voltage input at the AC input terminal and no voltage input at the DC input terminal, determining that the current working state is a general state, and outputting the AC power input at the AC input terminal to the motor;

[0017] When there is voltage input at the DC input terminal, determining that the current working state is a photovoltaic state, and outputting the DC power input at the DC input terminal to the motor;

[0018] When the current working state is the general state and the direct current output by the photovoltaic module is higher than a preset voltage, the current working state is converted from the general state to the photovoltaic state;

[0019] When the current working state is the photovoltaic state and the voltage output by the photovoltaic module is lower than the preset voltage, the current working state is converted from the photovoltaic state to the general state.

[0020] On the other hand, the current working state is converted from the general state to the photovoltaic state, including:

[0021] Control the inverter to decelerate and stop, disconnect from the AC module, convert the current working state to the photovoltaic state, and start according to the photovoltaic state after a preset time;

[0022] or controlling the frequency converter to decelerate to a preset frequency, disconnecting from the AC module, and converting the current working state to a photovoltaic state;

[0023] Or directly convert the current working state into the photovoltaic state and disconnect from the AC module.

[0024] On the other hand, it also includes a heat dissipation module, which includes a fan and a DC conversion module;

[0025] The control end of the DC conversion module is connected to the second control output end of the inverter, the input end of the DC conversion module is connected to the output end of the photovoltaic module, and the output end of the DC conversion module is connected to the power supply end of the fan;

[0026] The inverter is also used to control the DC conversion module to step down the DC power output by the photovoltaic module when the temperature of the inverter is higher than a preset temperature, so as to power the fan, and the fan is used to dissipate heat for itself.

[0027] On the other hand, the frequency converter is also used for:

[0028] According to the MTTP calculation strategy, maximum power point tracking is performed to obtain the first operating power;

[0029] According to the PID calculation strategy, the second operating power is obtained based on the deviation between the current power and the target power;

[0030] The current power is positively correlated with the pressure of the water flow in the pipe where the water pump is located, which is collected by the pressure sensor;

[0031] The smaller one of the first operating power and the second operating power is used as the operating power of the inverter.

[0032] In order to solve the above problems, the present invention also provides a voltaic water pump, comprising:

[0033] The control device of the photovoltaic water pump mentioned above;

[0034] A water pump, the water pump is arranged in a pipeline between the target container and the water storage device, and is used to pump water in the target container into the water storage device based on the control of the control device of the photovoltaic water pump;

[0035] The water storage device.

[0036] On the other hand, it also includes a high water level sensor and a low water level sensor;

[0037] The high water level sensor is arranged at a first preset depth in the water storage device, and the low water level sensor is arranged at a second preset depth in the target container, and both the high water level sensor and the low water level sensor are connected to the frequency converter of the control device of the photovoltaic water pump;

[0038] The high water level sensor is used to send a high water level signal to the frequency converter when the water level is higher than the depth at which the sensor is located, and the low water level sensor is used to send a low water level signal to the frequency converter when the water level is lower than the depth at which the sensor is located;

[0039] The frequency converter is also used to stop working when receiving the high water level signal or the low water level signal.

[0040] On the other hand, it also includes a high water level sensor, a middle water level sensor and a low water level sensor;

[0041] When the high water level sensor, the middle water level sensor and the low water level sensor are arranged in the target container in sequence from top to bottom, the high water level sensor, the middle water level sensor and the low water level sensor are all connected to the inverter of the control device of the photovoltaic water pump, the high water level sensor is used to send a high water level signal to the inverter when the water level is higher than the depth at which the sensor is located, the middle water level sensor is used to send a middle water level signal to the inverter when the water level is lower than the depth at which the sensor is located, and the low water level sensor is used to send a low water level signal to the inverter when the water level is lower than the depth at which the sensor is located, and the inverter is also used to operate at a first frequency when receiving the high water level signal, operate at a second frequency when only receiving the middle water level signal, and sleep when receiving the low water level signal, and the first frequency is higher than the second frequency;

[0042] When the high water level sensor, the middle water level sensor and the low water level sensor are arranged in the water storage device in sequence from top to bottom, the high water level sensor, the middle water level sensor and the low water level sensor are all connected to the frequency converter, the high water level sensor is used to send a high water level signal to the frequency converter when the water level is higher than the depth at which the sensor is located, the middle water level sensor is used to send a middle water level signal to the frequency converter when the water level is higher than the depth at which the sensor is located, and the low water level sensor is used to send a low water level signal to the frequency converter when the water level is lower than the depth at which the sensor is located, and the frequency converter is also used to operate at the first frequency when receiving the low water level signal, operate at the second frequency when receiving the middle water level signal, and sleep when receiving the high water level signal.

[0043] The present invention discloses a control device for a photovoltaic water pump and a photovoltaic water pump, which relate to the field of photovoltaics, and include a photovoltaic module, wherein the output end of the photovoltaic module is connected to the DC input end of a frequency converter, and is used to convert solar energy into DC power and then output it to the frequency converter; an AC module, wherein the input end of the AC module is connected to the mains, and the output end is connected to the AC input end of the frequency converter, and is used to output the mains to the frequency converter; a frequency converter, which is used to convert the DC power output by the photovoltaic module or the AC power output by the AC module into target AC power to drive a motor; and a motor, wherein the power supply end of the motor is connected to the output end of the frequency converter, and the output end is connected to the driving end of the water pump, and is used to drive the water pump. The AC module can also supply power to the frequency converter, thereby avoiding the unstable power supply voltage caused by the power supply of a single photovoltaic module, and the frequency converter can convert voltage based on DC power and AC power, so that the voltage driving the water pump is more stable, and at the same time, the usable time of the photovoltaic water pump is increased. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the prior art and the drawings required for use in the embodiments are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0045] Figure 1 A schematic diagram of the structure of a photovoltaic water pump provided by the present invention;

[0046] Figure 2 A schematic diagram of the structure of another photovoltaic water pump provided by the present invention;

[0047] Figure 3 A flow chart of power-on mode determination provided by the present invention;

[0048] Figure 4 A flow chart of a frequency converter control provided by the present invention;

[0049] Figure 5 A flow chart of determining power of a frequency converter provided by the present invention;

[0050] Figure 6 A schematic diagram of the structure of a water level sensor provided by the present invention disposed in a target container;

[0051] Figure 7 A schematic diagram of the operating frequency of a frequency converter of a water level sensor provided by the present invention disposed in a target container;

[0052] Figure 8 A schematic diagram of the structure of a water level sensor provided by the present invention disposed in a water storage device;

[0053] Fig. 9A schematic diagram of the operating frequency of a frequency converter in which a water level sensor provided by the present invention is arranged in a water storage device. DETAILED DESCRIPTION

[0054] The core of the present invention is to provide a control device for a photovoltaic water pump and a photovoltaic water pump. The AC module can also power the inverter, thereby avoiding the unstable power supply voltage caused by the power supply of a single photovoltaic module. The inverter can convert voltage based on DC and AC, and the voltage driving the water pump is more stable, while also increasing the service life of the photovoltaic water pump.

[0055] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0056] Figure 1 This is a schematic diagram of the structure of a photovoltaic water pump provided by the present invention. The control device of the photovoltaic water pump provided by the present invention includes:

[0057] Photovoltaic module 1, the output end of the photovoltaic module 1 is connected to the DC input end of the inverter 3, and is used to convert solar energy into DC power and then output it to the inverter 3;

[0058] AC module 2, the input end of the AC module 2 is connected to the AC power, and the output end is connected to the AC input end of the inverter 3, for outputting the AC power to the inverter 3;

[0059] The frequency converter 3 is used to convert the direct current output by the photovoltaic module 1 or the alternating current output by the alternating current module 2 into a target alternating current to drive the motor 4;

[0060] The motor 4 has a power supply end connected to the output end of the frequency converter 3 , and the output end is connected to the driving end of the water pump 5 for driving the water pump 5 .

[0061] When the sun shines, the photovoltaic module 1 can convert solar energy into electrical energy, and then supply power to the inverter 3. However, the photovoltaic module 1 cannot emit light at night due to the influence of sunlight, and cannot provide enough electrical energy on cloudy days, at sunrise or sunset, so it cannot provide 24-hour power supply, which reduces the use time of the water pump 5. In this application, an AC module 2 is added, and the AC module 2 is connected to the mains power supply, which can supplement the power supply of the photovoltaic module 1, that is, when the photovoltaic module 1 is not powered, the AC module 2 can supplement the power supply, thereby increasing the working time of the water pump 5. The mains power in this application can be a power grid or a generator 4, and this application does not make too many restrictions here.

[0062] The inverter 3 receives both AC and DC power, so the inverter 3 can realize the function of converting DC power into AC power, and can also transform AC power. It should be noted that the inverter 3 provided in the present application can be a separate control module used in conjunction with the inverter, and the control module of the inverter 3 is controlled when the preset power of the inverter 3 is calculated, or the control module in the inverter is improved in the algorithm, and the present application does not make too many restrictions here.

[0063] After the frequency converter 3 drives the motor 4 to work, it drives the water pump 5 to work, and the water pump 5 pumps the water in the target container 7 into the water storage device 8. The target container 7 can be a container, or a pool, a well or a river.

[0064] The present application provides a photovoltaic water pump control device, which relates to the photovoltaic field, and includes a photovoltaic module 1, which is used to convert solar energy into direct current for output; an alternating current module 2, which is used to output the mains power to a frequency converter 3; and a frequency converter 3, which is used to convert the direct current output by the photovoltaic module 1 or the alternating current output by the alternating current module 2 into a target alternating current to drive a motor 4. The alternating current module 2 can also supply power to the frequency converter 3, thereby avoiding the unstable power supply voltage caused by the power supply of a single photovoltaic module 1. The frequency converter 3 can convert voltage based on direct current and alternating current, and the voltage driving the water pump 5 is more stable, while increasing the usable time of the photovoltaic water pump 5.

[0065] Based on the above embodiments:

[0066] Figure 2 A schematic diagram of the structure of another photovoltaic water pump provided by the present invention;

[0067] In some embodiments, the photovoltaic module 1 includes a photovoltaic panel array 11, a rectifier bridge 12, a DC circuit breaker 13 and a voltage conversion module 14;

[0068] The output end of the photovoltaic panel array 11 is connected to the first end of the DC circuit breaker 13, the second end of the DC circuit breaker 13 is respectively connected to the input end of the voltage converter and the input end of the rectifier bridge 12, the second end of the rectifier bridge 12 is connected to the DC input end of the inverter 3, and the output end of the voltage conversion module 14 is connected to the first analog interface of the inverter 3;

[0069] The photovoltaic panel array 11 is used to convert solar energy into electrical energy, the rectifier bridge 12 is used for rectification, the DC circuit breaker 13 is used to input the electrical energy output by the photovoltaic panel array 11 into the inverter 3 when closed, and the voltage conversion module 14 is used to detect the voltage output by the photovoltaic panel array 11 and feed it back to the inverter 3.

[0070] After receiving sunlight, the photovoltaic panel array 11 can convert sunlight into electrical energy. A DC circuit breaker 13 is set at the output end of the photovoltaic panel array 11, and the on and off of the DC circuit breaker are determined by the user. Considering that the voltage output by the photovoltaic panel array 11 may not be stable enough, a rectifier bridge 12 is set to stabilize the voltage, thereby achieving more stable power supply to the inverter 3. In addition, in order to ensure stable power supply to the photovoltaic module 1, a voltage conversion module 14 is set to collect the voltage output by the photovoltaic panel array 11, and the collected result is output to the inverter 3. The inverter 3 can determine whether the conditions are met based on the voltage currently output by the photovoltaic panel array 11.

[0071] In some embodiments, the AC module 2 includes an AC circuit breaker 21, an AC contactor 22, and an auxiliary contact 23;

[0072] The first end of the AC circuit breaker 21 is connected to the mains, the second end of the AC circuit breaker 21 is connected to the first end of the AC contactor 22, the second end of the AC contactor 22 is connected to the AC input end of the frequency converter 3, the control end of the AC contactor 22 is connected to the first control output end of the frequency converter 3, the first end of the auxiliary contact 23 is connected to the feedback end of the AC contactor 22, and the second end of the auxiliary contact 23 is connected to the first switch quantity interface of the frequency converter 3;

[0073] The AC contactor 22 is used to connect the AC power to the frequency converter 3 when it is turned on, and the auxiliary contact 23 is used to determine the connection state of the AC contactor 22 and feed it back to the frequency converter 3.

[0074] The on and off of the AC circuit breaker 21 are determined by the user, and the frequency converter 3 controls the on and off of the AC contactor 22. When the AC contactor 22 is closed, AC power is supplied to the frequency converter 3. The auxiliary contact 23 can assist in determining the on condition of the AC contactor 22.

[0075] Figure 3 A flow chart of power-on mode determination provided by the present invention;

[0076] Figure 4 A flow chart of a frequency converter control provided by the present invention;

[0077] Figure 2 The switch terminal 3 in is the first switch quantity interface.

[0078] In some embodiments, converting the direct current output by the photovoltaic module or the alternating current output by the alternating current module into a target alternating current to drive a motor includes:

[0079] When there is voltage input at the AC input terminal and no voltage input at the DC input terminal, the current working state is determined to be a general state, and the AC power input at the AC input terminal is output to the motor 4;

[0080] When there is voltage input at the DC input terminal, it is determined that the current working state is the photovoltaic state, and the DC power input at the DC input terminal is output to the motor 4;

[0081] When the current working state is the general state and the DC power output by the photovoltaic module 1 is higher than the preset voltage, the current working state is converted from the general state to the photovoltaic state;

[0082] When the current working state is the photovoltaic state, the voltage output by the photovoltaic module 1 is lower than the preset voltage or the working frequency of the inverter 3 is lower, the current working state is converted from the photovoltaic state to the general state.

[0083] When there is only AC input (detected by auxiliary contact 23) and no photovoltaic voltage input (detected by voltage detection module whether there is photovoltaic power input), the driver runs in general mode. At this time, it is not MPPT (Maximum Power Point Tracking) working mode. The MPPT working mode will adjust the frequency according to the voltage, and the general mode will not adjust the frequency.

[0084] When the photovoltaic voltage is input (when the voltage detection module detects sufficient voltage), regardless of whether the auxiliary contact 23 is closed, the driver runs in photovoltaic mode when powered on. The photovoltaic mode uses the MPPT algorithm and automatically adjusts the frequency according to the power supply energy.

[0085] When running in the general mode, the voltage converted by the voltage conversion module 14 obtained through the first analog interface is monitored in real time, and the voltage is used to determine whether the photovoltaic panel voltage meets the switching requirements. If the switching requirements are met, the system switches to the photovoltaic mode according to the preset mode. This is because when switching directly from AC power supply to photovoltaic power supply, when the lighting conditions are poor, a low voltage fault is prone to occur. The purpose of setting three modes is to take into account both flexible switching and fast switching.

[0086] In some embodiments, converting the current working state from the general state to the photovoltaic state includes:

[0087] Control the inverter 3 to decelerate and stop, disconnect from the AC module 2, convert the current working state to the photovoltaic state, and start according to the photovoltaic state after a preset time;

[0088] Or control the inverter 3 to decelerate to a preset frequency, disconnect from the AC module 2, and convert the current working state into a photovoltaic state;

[0089] Or directly convert the current working state to the photovoltaic state and disconnect from the AC module 2.

[0090] Preset mode 1, deceleration and shutdown, after a period of AC power supply, and when the photovoltaic voltage is sufficient, try to switch to photovoltaic mode. At this time, the photovoltaic power supply energy may be insufficient, so try to run MPPT again after shutdown to avoid low voltage failure---flexible switching. Therefore, according to the set deceleration slope, after deceleration to 0 frequency, stop outputting the deceleration and shutdown control requirements, the inverter 3 outputs a failure signal, disconnects the AC contactor 22, and the inverter 3 switches to the photovoltaic mode, and starts in the photovoltaic mode after the preset delay time.

[0091] Preset mode 2 decelerates to a predetermined frequency, switches to the photovoltaic operation mode (the target voltage is switched to the current bus voltage of the inverter 3), and disconnects the AC contactor 22 through the inverter 3.

[0092] The preset mode three directly switches to the photovoltaic mode operation (the target voltage is switched to the current bus voltage of the inverter 3 ), and the AC contactor 22 is disconnected through the inverter 3 .

[0093] In some embodiments, a heat dissipation module is also included, and the heat dissipation module includes a fan 61 and a DC conversion module 62;

[0094] The control end of the DC conversion module 62 is connected to the second control output end of the inverter 3, the input end of the DC conversion module 62 is connected to the output end of the photovoltaic module 1, and the output end of the DC conversion module 62 is connected to the power supply end of the fan 61;

[0095] When the temperature of the inverter 3 is higher than the preset temperature, the DC conversion module 62 is controlled to reduce the voltage of the DC power output by the photovoltaic module 1 to supply power to the fan 61, and the fan 61 is used to dissipate heat for itself.

[0096] By detecting the temperature of the inverter 3, when it reaches a preset value, the DC conversion module 62 is enabled through the second control output terminal to drive the fan 61, thereby improving the derating problem of the inverter 3 caused by environmental problems. At the same time, unnecessary losses are reduced through the controllable cooling fan 61 to improve the overall efficiency.

[0097] Figure 5 A flow chart of determining power of a frequency converter provided by the present invention;

[0098] In some embodiments, the frequency converter 3 is further used for:

[0099] According to the MTTP calculation strategy, maximum power point tracking is performed to obtain the first operating power;

[0100] According to the PID calculation strategy, the second operating power is obtained based on the deviation between the current power and the target power;

[0101] The current power is positively correlated with the pressure of the water flow in the pipe where the pump is located, which is collected by the pressure sensor;

[0102] The smaller one between the first operating power and the second operating power is used as the operating power of the frequency converter 3 .

[0103] Frequency source 1 MPPT calculates the operating frequency F1, and frequency source 2 external speed control module such as PID speed control (closed-loop control through the signal detected by the analog interface) calculates the operating frequency F2. The start F2 frequency is handed over to the frequency limit module (dynamic modification of the output upper limit, modification of the upper limit frequency inside the MPPT), which dynamically updates the upper limit frequency and implements the update of the upper limit of the MPPT internal calculation unit to reduce the adjustment delay. The final output preset frequency F3 is handed over to inverter 3 for execution.

[0104] A quick and easy way to make two speed control systems compatible: frequency source 1 outputs normally, and frequency source 2 limits the upper limit of the overall frequency source, so that both frequency sources are effective at the same time. However, if you only adjust the upper limit of the overall output without dealing with the frequency limit of the MPPT, the final output will be limited to a very low level, but the MPPT frequency will be very high. When reverse adjustment occurs, the MPPT frequency will not respond. Therefore, frequency source 2 must not only limit the upper limit of the overall frequency output, but also the upper limit of the MPPT frequency.

[0105] The pressure sensor 91 is arranged in the pipeline and connected to the second analog quantity interface of the frequency converter 3, and is used to collect the pressure of the water flow in the pipeline so as to realize constant pressure control of the water flow.

[0106] In order to achieve a constant water pressure in the pipeline where the water pump 5 is located, the pressure of the water flow in the water pipe is collected, and then the water pump 5 is controlled based on the pressure deviation.

[0107] The present application also provides a photovoltaic water pump, comprising:

[0108] The control device of the photovoltaic water pump mentioned above;

[0109] A water pump 5, which is arranged in a pipeline between the target container 7 and the water storage device 8, and is used to pump water in the target container 7 into the water storage device 8 based on the control of the photovoltaic water pump control device;

[0110] Water storage device 8.

[0111] In some embodiments, a high water level sensor 92 and a low water level sensor 93 are also included;

[0112] The high water level sensor 92 is arranged at a first preset depth in the water storage device 8, and the low water level sensor 93 is arranged at a second preset depth in the target container 7, and both the high water level sensor 92 and the low water level sensor 93 are connected to the frequency converter of the control device of the photovoltaic water pump;

[0113] The high water level sensor 92 is used to send a high water level signal to the frequency converter 3 when the water level is higher than the depth at which the sensor is located, and the low water level sensor 93 is used to send a low water level signal to the frequency converter 3 when the water level is lower than the depth at which the sensor is located;

[0114] The frequency converter is also used to stop working when receiving a high water level signal or a low water level signal.

[0115] A low water level sensor 93 is added. When the low water level is detected to be valid, the inverter 3 needs to go into sleep mode to prevent the water pump 5 from running dry. For water injection applications, a high water level sensor 92 is added. When the high water level is detected to be valid, the inverter 3 needs to go into sleep mode to prevent the pool from overflowing.

[0116] Detect high water level and low water level signals respectively. When the high water level sleep flag is not set, it is judged that the high water level is valid and the judgment time is up, and the high water level sleep flag is set; when the high water level sleep flag is set, it is judged that the high water level is invalid and the judgment time is up, and the high water level sleep flag is reset. The subsequent processing logic is controlled by the general sleep control logic. When the low water level sleep flag is not set, it is judged that the low water level is invalid and the judgment time is up, and the low water level sleep flag is set; when the low water level sleep flag is set, it is judged that the low water level is valid and the judgment time is up, and the low water level sleep flag is reset. The subsequent processing logic is controlled by the general sleep control logic.

[0117] In some embodiments, a high water level sensor 92, a middle water level sensor 94 and a low water level sensor 93 are also included;

[0118] When the high water level sensor 92, the middle water level sensor 94 and the low water level sensor 93 are arranged in the target container 7 from top to bottom, the high water level sensor 92, the middle water level sensor 94 and the low water level sensor 93 are all connected to the inverter 3 of the control device of the photovoltaic water pump, the high water level sensor 92 is used to send a high water level signal to the inverter 3 when the water level is higher than the depth at which it is located, the middle water level sensor 94 is used to send a middle water level signal to the inverter 3 when the water level is lower than the depth at which it is located, and the low water level sensor 93 is used to send a low water level signal to the inverter 3 when the water level is lower than the depth at which it is located, and the inverter 3 is also used to operate at a first frequency when receiving a high water level signal, operate at a second frequency when only receiving a middle water level signal, and sleep when receiving a low water level signal, and the first frequency is higher than the second frequency;

[0119] When the high water level sensor 92, the middle water level sensor 94, and the low water level sensor 93 are arranged in the water storage device 87 from top to bottom in sequence, the high water level sensor 92, the middle water level sensor 94, and the low water level sensor 93 are all connected to the frequency converter 3 of the control device of the photovoltaic water pump. The high water level sensor 92 is used to send a high water level signal to the frequency converter 3 when the water level is higher than its own depth. The middle water level sensor 94 is used to send a middle water level signal to the frequency converter 3 when the water level is higher than its own depth. The low water level sensor 93 is used to send a low water level signal to the frequency converter 3 when the water level is lower than its own depth. The frequency converter 3 is further used to operate at a first frequency when receiving the low water level signal, operate at a second frequency when receiving the middle water level signal, and go into sleep mode when receiving the high water level signal.

[0120] Figure 6 FIG. is a schematic structural diagram of a water level sensor provided by the present invention arranged in a target container;

[0121] Figure 7 FIG. is a schematic diagram of the operating frequency of the frequency converter of a water level sensor provided by the present invention arranged in a target container;

[0122] When the high water level sensor 92, the middle water level sensor 94, and the low water level sensor 93 are arranged in the target container 7 from top to bottom in sequence, it is understood to be for pumping applications. When the water level is higher than the high water level, start according to the given value A. When it drops to the middle water level, switch to the given value B (B < A). When the water level continues to be lower than the low water level, go into sleep mode until the water level is higher than the high water level and restart. When running according to the given value A after waking up, if the water level is lower than the middle water level, the given value is switched to the given value B, and when it rises to the high water level subsequently, switch to the given value A again. A is the first frequency and B is the second frequency.

[0123] Figure 8 FIG. is a schematic structural diagram of a water level sensor provided by the present invention arranged in a water storage device;

[0124] Fig. 9 FIG. is a schematic diagram of the operating frequency of the frequency converter of a water level sensor provided by the present invention arranged in a water storage device.

[0125] When the high water level sensor 92, the middle water level sensor 94, and the low water level sensor 93 are arranged in the water storage device 8 from top to bottom in sequence, it is understood to be for irrigation applications. When starting with the water level lower than the low water level, operate according to the given value A. When the water level is higher than the middle water level, operate according to the given value B (B < A). When the water level is higher than the high water level, go into sleep mode until the water level is lower than the low water level and restart. When running according to the given value A after waking up, if the water level is higher than the middle water level, then switch to the given value B, and when the water level is lower than the low water level again, switch to the given value A.

[0126] Multi-level water level control can reduce frequent starts and stops, and reduce the wear on the machinery during the start and stop stages.

[0127] It should also be noted that, in this specification, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "comprise", "include" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the statement "comprises a ..." does not exclude the presence of other identical elements in the process, method, article or device including the element.

[0128] Professionals may further appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of the two. In order to clearly illustrate the interchangeability of hardware and software, the composition and steps of each example have been generally described in the above description according to function. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professionals and technicians may use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of the present invention.

[0129] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A photovoltaic water pump control device, characterized in that: include: A photovoltaic module, wherein the output end of the photovoltaic module is connected to the DC input end of the inverter, and is used to convert solar energy into DC power and then output it to the inverter; An AC module, the input end of which is connected to the mains, and the output end of which is connected to the AC input end of the frequency converter, for outputting the mains to the frequency converter; The frequency converter is used to convert the direct current output by the photovoltaic module or the alternating current output by the alternating current module into target alternating current to drive the motor; The motor, wherein the power supply end of the motor is connected to the output end of the frequency converter, and the output end is connected to the driving end of the water pump, is used to drive the water pump.

2. The control device of the photovoltaic water pump according to claim 1, characterized in that: The photovoltaic module includes a photovoltaic panel array, a rectifier bridge, a DC circuit breaker and a voltage conversion module; The output end of the photovoltaic panel array is connected to the first end of the DC circuit breaker, the second end of the DC circuit breaker is respectively connected to the input end of the voltage converter and the input end of the rectifier bridge, the second end of the rectifier bridge is connected to the DC input end of the inverter, and the output end of the voltage conversion module is connected to the first analog interface of the inverter; The photovoltaic panel array is used to convert solar energy into electrical energy, the rectifier bridge is used for rectification, the DC circuit breaker is used to input the electrical energy output by the photovoltaic panel array into the inverter when closed, and the voltage conversion module is used to detect the voltage output by the photovoltaic panel array and feed it back to the inverter.

3. The control device of the photovoltaic water pump according to claim 1, characterized in that: The AC module includes an AC circuit breaker, an AC contactor and auxiliary contacts; The first end of the AC circuit breaker is connected to the mains, the second end of the AC circuit breaker is connected to the first end of the AC contactor, the second end of the AC contactor is connected to the AC input end of the frequency converter, the control end of the AC contactor is connected to the first control output end of the frequency converter, the first end of the auxiliary contact is connected to the feedback end of the AC contactor, and the second end of the auxiliary contact is connected to the first switch value interface of the frequency converter; The AC contactor is used to connect AC power to the frequency converter when it is turned on, and the auxiliary contact is used to determine the connection state of the AC contactor and feed it back to the frequency converter.

4. The control device of the photovoltaic water pump according to claim 1, characterized in that: Converting the direct current output by the photovoltaic module or the alternating current output by the alternating current module into target alternating current to drive a motor, comprising: When there is voltage input at the AC input terminal and no voltage input at the DC input terminal, determining that the current working state is a general state, and outputting the AC power input at the AC input terminal to the motor; When there is voltage input at the DC input terminal, determining that the current working state is a photovoltaic state, and outputting the DC power input at the DC input terminal to the motor; When the current working state is the general state and the direct current output by the photovoltaic module is higher than a preset voltage, the current working state is converted from the general state to the photovoltaic state; When the current working state is the photovoltaic state and the voltage output by the photovoltaic module is lower than the preset voltage, the current working state is converted from the photovoltaic state to the general state.

5. The control device of the photovoltaic water pump according to claim 4, characterized in that: Convert the current working state from the general state to the photovoltaic state, including: Control the inverter to decelerate and stop, disconnect from the AC module, convert the current working state to the photovoltaic state, and start according to the photovoltaic state after a preset time; or controlling the frequency converter to decelerate to a preset frequency, disconnecting from the AC module, and converting the current working state to a photovoltaic state; Or directly convert the current working state into the photovoltaic state and disconnect from the AC module.

6. The control device of the photovoltaic water pump according to claim 1, characterized in that: It also includes a heat dissipation module, which includes a fan and a DC conversion module; The control end of the DC conversion module is connected to the second control output end of the inverter, the input end of the DC conversion module is connected to the output end of the photovoltaic module, and the output end of the DC conversion module is connected to the power supply end of the fan; The inverter is also used to control the DC conversion module to step down the DC power output by the photovoltaic module when the temperature of the inverter is higher than a preset temperature, so as to power the fan, and the fan is used to dissipate heat for itself.

7. The control device for a photovoltaic water pump according to any one of claims 1 to 6, characterized in that: The frequency converter is also used for: According to the MTTP calculation strategy, maximum power point tracking is performed to obtain the first operating power; According to the PID calculation strategy, the second operating power is obtained based on the deviation between the current power and the target power; The current power is positively correlated with the pressure of the water flow in the pipe where the water pump is located, which is collected by the pressure sensor; The smaller one of the first operating power and the second operating power is used as the operating power of the inverter.

8. A photovoltaic water pump, characterized in that: include: A control device for a photovoltaic water pump as claimed in any one of claims 1 to 7; A water pump, the water pump is arranged in a pipeline between the target container and the water storage device, and is used to pump water in the target container into the water storage device based on the control of the control device of the photovoltaic water pump; The water storage device.

9. The photovoltaic water pump according to claim 8, characterized in that: Also includes a high water level sensor and a low water level sensor; The high water level sensor is arranged at a first preset depth in the water storage device, and the low water level sensor is arranged at a second preset depth in the target container, and both the high water level sensor and the low water level sensor are connected to the frequency converter of the control device of the photovoltaic water pump; The high water level sensor is used to send a high water level signal to the frequency converter when the water level is higher than the depth at which the sensor is located, and the low water level sensor is used to send a low water level signal to the frequency converter when the water level is lower than the depth at which the sensor is located; The frequency converter is also used to stop working when receiving the high water level signal or the low water level signal.

10. The photovoltaic water pump according to claim 8, characterized in that: It also includes a high water level sensor, a middle water level sensor and a low water level sensor; When the high water level sensor, the middle water level sensor and the low water level sensor are arranged in the target container in sequence from top to bottom, the high water level sensor, the middle water level sensor and the low water level sensor are all connected to the inverter of the control device of the photovoltaic water pump, the high water level sensor is used to send a high water level signal to the inverter when the water level is higher than the depth at which the sensor is located, the middle water level sensor is used to send a middle water level signal to the inverter when the water level is lower than the depth at which the sensor is located, and the low water level sensor is used to send a low water level signal to the inverter when the water level is lower than the depth at which the sensor is located, and the inverter is also used to operate at a first frequency when receiving the high water level signal, operate at a second frequency when only receiving the middle water level signal, and sleep when receiving the low water level signal, and the first frequency is higher than the second frequency; When the high water level sensor, the middle water level sensor and the low water level sensor are arranged in the water storage device in sequence from top to bottom, the high water level sensor, the middle water level sensor and the low water level sensor are all connected to the frequency converter, the high water level sensor is used to send a high water level signal to the frequency converter when the water level is higher than the depth at which the sensor is located, the middle water level sensor is used to send a middle water level signal to the frequency converter when the water level is higher than the depth at which the sensor is located, and the low water level sensor is used to send a low water level signal to the frequency converter when the water level is lower than the depth at which the sensor is located, and the frequency converter is also used to operate at the first frequency when receiving the low water level signal, operate at the second frequency when receiving the middle water level signal, and sleep when receiving the high water level signal.

Images