Photovoltaic input battery-free energy storage oxygenation water pump driving control method and control circuit

Abstract

The invention discloses a photovoltaic input battery-free energy storage oxygenation water pump driving control method and a control circuit. A universal controller based on the implementation of the invention can be flexibly matched with a permanent magnet motor with unidentified parameters to drive an oxygenation water pump. The controller and the pump are connected with the oxygenation water pump through the variable-length three-phase cable, and the starting operation step automatically recognizes internal resistance parameters and sensing values of the oxygenation water pump and the variable-length three-phase cable and automatically generates operation regulator parameters. The position angle of the rotor of the non-inductive permanent magnet motor is observed under low voltage and high current, the pump motor is ensured not to be out of step during operation, and the operation efficiency and the photovoltaic tracking accuracy are improved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of photovoltaic oxygenation driving, and relates to a photovoltaic input battery-free energy storage oxygenation water pump driving control method and a control circuit. BACKGROUND

[0002] In the fields of aquaculture and water body treatment, oxygenation equipment is the key to maintaining the ecological balance of water bodies and ensuring production efficiency. With the popularization of new energy technology, photovoltaic oxygenation water pumps, with the core advantages of "zero electricity cost, low emission and easy maintenance", are gradually replacing traditional electric oxygenation water pumps and becoming the preferred solution for water oxygenation. By converting solar energy into mechanical energy, it realizes efficient oxygenation of water bodies and responds to the concept of green development, reducing the long-term operating costs for users.

[0003] In the subcategory of photovoltaic oxygenation water pumps, the battery-free photovoltaic oxygenation water pump system is characterized by "simplified structure and lower cost" and has become the preferred solution for specific scenarios. It eliminates the need for traditional photovoltaic oxygenation water pump storage batteries and is composed only of photovoltaic modules, control systems and oxygenation water pump main bodies, directly relying on real-time solar energy to drive the oxygenation water pump to operate. However, with the unique advantage of significantly lower cost and faster return on investment, it occupies a certain market space. The battery-free system eliminates this core component, significantly reducing the initial investment pressure on users and eliminating the need to bear the depreciation and loss costs of the battery.

[0004] In the arrangement of oxygenation water pumps in aquaculture and water environments, the controller is often centrally arranged in a shore control cabinet for convenience, and the oxygenation water pump is connected through a long cable. The length, thickness and material of the cable seriously affect the operating parameters of the controller and the internal resistance of the permanent magnet oxygenation water pump, causing reliability problems such as pump stall and low operating efficiency. Overcoming the variability of the operating environment through the design of the control method has become a pressing problem. SUMMARY

[0005] The present application overcomes the shortcomings of the prior art and provides a photovoltaic input battery-free energy storage oxygenation water pump driving control method and control circuit.

[0006] To achieve the above purpose, the following technical solutions are adopted: A photovoltaic input battery-free energy storage oxygenation water pump driving control method, comprising the following steps: Step 1: Obtain system parameters and perform power-on self-test. When the current photovoltaic panel voltage input meets the starting voltage, the subsequent process is started. Step 2: Calculate the oxygenation water pump line resistance and line inductance by gradually increasing the small pulse width voltage amplitude and detecting the response current and response voltage, and calculate the discrete proportion and integral parameter values of the current loop PI regulator based on the line inductance and line resistance. Step 3: Start the motor and gradually increase the frequency, detect the photovoltaic input voltage, motor drive voltage and load power, and switch to photovoltaic closed-loop control when the motor drive voltage reaches the voltage switching threshold; Step 4: The photovoltaic closed-loop control includes a limiting factor algorithm module, a photovoltaic input adjustment module, and a permanent magnet synchronous motor drive module. The permanent magnet synchronous motor drive module controls the vector drive of the permanent magnet synchronous motor, the photovoltaic input adjustment module tracks the maximum power point of the photovoltaic panel, and the limiting factor algorithm module responds to limiting factors.

[0007] Furthermore, in step 1, by acquiring the input bus voltage, when the voltage exceeds the low-voltage protection voltage, the current sampling circuit signal reference is acquired. The average value after sampling is used to calculate the reference value. In order to avoid the introduction of error offset when the reference value acquired by the digital control power supply under photovoltaic low voltage is compared with the actual working value, the error offset is avoided.

[0008] Furthermore, in step 2, the calculation of the oxygenation pump line resistance includes: gradually increasing the amplitude of the small pulse width voltage, increasing the current value to the target current value and stabilizing it within the threshold range, recording the current value and voltage value once, and calculating the oxygenation pump line resistance based on the voltage value and current value recorded twice consecutively.

[0009] Furthermore, in step 2, the calculation of the oxygenation pump line inductance includes: applying a constant amplitude AC detection voltage stepwise with a fixed electrical angle; calculating the power factor parameter based on the response voltage, current amplitude, and cumulative power detection point value; and calculating the oxygenation pump line inductance based on the power factor parameter.

[0010] Furthermore, in step 3, the voltage switching threshold is 5V.

[0011] Furthermore, the limiting factors mentioned in step 4 include voltage utilization rate, controller temperature, oxygenation pump motor power, and oxygenation pump motor speed. The current limit values ​​corresponding to each limiting factor are integrated through the current limiting factor merging module to limit the integral regulator amplitude and output reference current amplitude of the voltage loop PI regulator.

[0012] Furthermore, in step 4, the photovoltaic input regulation module includes a photovoltaic regulation unit and an input voltage loop PI regulator.

[0013] Furthermore, in step 4, the permanent magnet synchronous motor drive module includes a rotor angle observer, a current loop PI regulator, an output dead zone voltage compensation unit, a current acquisition unit, and a three-phase power drive unit.

[0014] A photovoltaic oxygenation water pump control hardware drive circuit includes: Solar photovoltaic panels are used to power the oxygenation pump and digital control system. The DC bus is equipped with a support capacitor to provide drive power and buffer the motor start-up detection and closed-loop drive process; Storage chips are used to store system parameter configurations; The differential current sampling circuit sets the zero point of the current value corresponding to the non-zero reference value of the current sampling signal, and works in conjunction with voltage sampling to obtain operating parameters; The drive signal and sampling trigger module is used to generate power transistor switching signals based on drive voltage parameters; The inverter current sampling circuit uses a three-phase full-bridge drive circuit to output modulated drive based on the calculated voltage. The three-phase cable, with a variable length structure, connects the half-bridge output of the three-phase full-bridge circuit to the oxygenation pump load. The oxygenation pump is equipped with a built-in permanent magnet synchronous motor, which drives the pump head to operate. The current sampling resistor is connected to the drain of the lower power transistor in the three-phase full-bridge circuit. When the lower power transistor of the half-bridge is turned on, the current value is calculated based on the sampling trigger signal.

[0015] In summary, the advantages of this invention are: 1. The universal controller based on this invention can flexibly match the permanent magnet motor driven oxygenation pump with unidentified parameters. The controller is connected to the pump via a variable-length three-phase cable. During startup, the controller automatically identifies the internal resistance parameters and inductance of the oxygenation pump and the variable-length three-phase cable, and automatically generates operating regulator parameters. This ensures that the rotor position angle of the sensorless permanent magnet motor can be observed under low voltage and high current conditions, ensuring that the pump motor does not lose synchronization, thus improving operating efficiency and photovoltaic tracking accuracy.

[0016] 2. The control method designed in this invention enables the controller to vector drive the permanent magnet synchronous motor, and achieves maximum power point tracking of the photovoltaic panel in a battery-free energy storage hardware topology through motor drive, thereby achieving maximum load efficiency oxygenation operation and reducing the hardware procurement cost of the photovoltaic oxygenation water pump system.

[0017] 3. The control method of this invention simultaneously responds to external photovoltaic voltage fluctuations, controller operating temperature, and motor rated speed adjustment limitations. The control structure is simple and has a high response frequency, effectively ensuring that the controller operates within the normal operating range. Attached Figure Description

[0018] Figure 1 This is a block diagram of the controller hardware circuit in one embodiment of the present invention; Figure 2 This is a flowchart of the startup steps according to an embodiment of the present invention.

[0019] Figure 3 This is an embodiment of the closed-loop control algorithm framework of the present invention. Detailed Implementation

[0020] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that, unless otherwise specified, the following embodiments and features described therein can be combined with each other.

[0021] It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of the present invention. Therefore, the drawings only show the components related to the present invention and are not drawn according to the actual number, shape and size of the components. In actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0022] In this embodiment of the invention, all directional indicators (such as up, down, left, right, front, back, lateral, longitudinal, etc.) are only used to explain the relative positional relationship and movement of each component in a specific posture. If the specific posture changes, the directional indicator will also change accordingly.

[0023] Due to installation errors and other reasons, the parallel relationship referred to in the embodiments of the present invention may actually be an approximate parallel relationship, and the perpendicular relationship may actually be an approximate perpendicular relationship.

[0024] This invention provides a photovoltaic oxygenation water pump drive control circuit, the principle block diagram of which is shown below. Figure 1 As shown, the hardware drive circuit includes: a solar photovoltaic panel provides power to the aerator pump and digital control; a DC bus uses a supporting capacitor to provide drive power and buffer the motor start-up detection process and closed-loop drive process; the embodiment obtains system parameter configuration from the memory chip; the process control executes the aerator pump load drive and parameter setting according to the start-up steps and closed-loop control algorithm; a differential current sampling circuit sets the current value zero point corresponding to the non-zero reference value of the current sampling signal, and calculates the operating parameters with the voltage sampling; the control flow calculates the motor drive voltage parameter data; the drive signal and sampling trigger module generates the power tube switching signal according to the drive voltage parameters; the inverter current sampling circuit uses a three-phase full-bridge drive circuit to modulate the drive output according to the calculated voltage; the half-bridge output of the three-phase full-bridge circuit is connected to the aerator pump load through a variable-length three-phase cable; the permanent magnet synchronous motor built into the pump load drives the pump head to spray water out. The current sampling resistor is connected to the drain of the lower power tube of the three-phase full-bridge circuit, and calculates the current value according to the sampling trigger signal when the lower power tube of the half-bridge is turned on.

[0025] This invention provides a method for driving and controlling an oxygenation water pump with photovoltaic input and no battery storage, specifically including the following steps: Step 1: Obtain operating parameters according to system settings and perform power-on self-test. Obtain setting parameters such as product model, rated power, operating voltage range, starting voltage, maximum current, and speed limit. In some preferred embodiments, the setting parameters include: rated power 800W, rated current 15A, photovoltaic input operating voltage range 24V-110V, low-voltage protection voltage 20V, operating ambient temperature 0-60 degrees Celsius, maximum operating temperature of power devices 90 degrees Celsius, drive PWM frequency sampling 10KHz, and according to the operating power requirements, select a 140V, 80A maximum current, 9.2 milliohm MOSFET for the three-phase full-bridge circuit, with a current sampling range of ±30A, and a bus capacitor value C of 980uF. Acquire the input bus voltage. When the voltage exceeds the low-voltage protection voltage, start acquiring the current sampling circuit signal reference. Calculate the reference value by averaging the samples. To avoid error offset introduced by comparing the reference value obtained by the digital control power supply under photovoltaic low voltage with the actual operating value. Determine whether the current photovoltaic panel voltage input has reached the starting voltage. If the starting voltage condition is met, start the starting process.

[0026] Step 2: Identify the resistance of the oxygenation pump line and check for short circuits in the external motor interface of the small pulse voltage detection control hardware. Charge the bootstrap capacitor of the inverter drive circuit power switch drive circuit. Calculate the small pulse width voltage amplitude based on the MOS internal resistance and input voltage, and gradually increase the applied small pulse width voltage amplitude. During this process, detect the current value of each phase and check for overcurrent protection. If a protection fault occurs, return to the waiting state until the response current value increases to the target current value and the current change stabilizes within the threshold range. Record the current pulse width value and the current value of each phase. Set the voltage value again based on the current voltage value and wait for the current change to stabilize within the threshold range. Record the current pulse width value and the current value of each phase. Calculate the pump line resistance based on the two recorded current and voltage values.

[0027] Specifically, to avoid short circuits in the wiring, the initial detection pulse width voltage can be calculated using the following formula: In the formula The dead time for the half-bridge drive is set to 1µs in this embodiment. To drive the PWM frequency, This is the bus input voltage value. The power consumption is due to the internal resistance of the electromagnetic coil. To limit the current of the power transistor, it is set to 40 amps here, based on the maximum current of the power transistor.

[0028] The average current sample value is calculated every 10ms. When the change in current amplitude from the previous value is less than 0.1 amperes, the amplitude of the applied small pulse width voltage is gradually increased. The three-phase inverter circuit is debugged and injected using SVPWM mode. ,set up The value is 0, and in the example, it increases every 10ms. 0.2V voltage, until Once the phase current reaches 1 ampere, wait for the current change to stabilize within the threshold range, and record the current voltage value. and Current value. Increase again. When the voltage reaches 2 amps, record the current voltage value. and Record the current value. After recording, turn off the voltage output until the current output returns to zero, then proceed to step three.

[0029] Based on the impact of the difference in current and voltage between the two steps on the driving dead zone and conduction time on the detected value, the line resistance value is calculated using the following formula: .

[0030] Step 3: Apply a constant amplitude AC detection voltage gradually at a fixed electrical angle. With the pump in a stationary stall state, calculate the power factor parameter based on the response voltage, current amplitude, and cumulative power detection point value. Calculate the linear inductance of the pump motor based on the power factor parameter.

[0031] use As the AC modulation voltage amplitude, set vector drive Coordinate system reference voltage value: In the formula To detect the sinusoidal frequency, the pump is in a stationary locked state. At this time, the U-phase of the three-phase inverter generates a sinusoidal current with a certain phase corresponding to the detected sinusoidal voltage. Start with zero and gradually increase the frequency until the voltage, current, phase, and power factors reach the 0.6-0.8 range. Wait for the power factor to stabilize, then calculate the motor inductance value. Active power calculation method: Apparent power is calculated as follows: , The effective value of the current is: , The calculation method for the inductance of the oxygenation water pump motor is as follows: .

[0032] Step 4: Based on the inductance of the water pump line and line resistance Calculate the discretized proportional and integral parameter values ​​of the current loop PI regulator: .

[0033] In the formula For the current step-over response time, at the driving PWM frequency The value range for 10K is 0.005s to 0.05s, and the value in this example is 0.01s. The input voltage value is the bus input voltage. In this example, the maximum input voltage is 110V. The amplification factor is calculated for the current and is set to 1. To use the voltage per-unit factor, the example uses a value of 32767.

[0034] Step 5: The initial starting current drives the water pump motor to start, and the motor drive frequency is gradually increased. In this embodiment, the motor current amplitude is set to 3 amps. Simultaneously, the photovoltaic input voltage, motor drive voltage, and water pump load power are detected. During this process, it is determined whether the input photovoltaic voltage is within the minimum operating voltage range when the load power increases. It is then determined whether the motor drive voltage has reached the voltage switching threshold, and photovoltaic closed-loop control is initiated. In this embodiment, the voltage switching threshold is set to 5V. The rotor flux linkage is calculated based on the permanent magnet motor flux linkage. .

[0035] Step 6: Closed-loop operation of the photovoltaic driver. (Refer to...) Figure 3 The illustrated closed-loop control algorithm framework for the photovoltaic aeration water pump demonstrates how the controller vector-driven permanent magnet synchronous motor propels the aeration water pump to operate stably. Load adjustment of the aeration water pump tracks the maximum power point of the photovoltaic panel, ensuring maximum load efficiency for aeration operation. Simultaneously, the algorithm responds to external factors such as photovoltaic voltage fluctuations, controller operating temperature, and motor rated speed adjustment limitations, ensuring the controller operates within its normal operating range.

[0036] The average power of the motor power limiting module during the cycle is calculated by combining the drive voltage generated by the PI regulator and the drive current obtained by current sampling, according to the following formula: In the formula The average power of the current in a single cycle is used to determine one pump operation cycle based on the rotor angle observer, while simultaneously counting the number of times the current accumulates during a single-cycle PWM interruption. . , , , For vector control Convert voltage and current values ​​to coordinate systems. Accumulate and calculate the periodic power value and its average. Calculate the current limit using a PI controller based on the power average and amplitude.

[0037] Since the adjustment range and speed range of the booster pump are relatively fixed, in order to optimize the power regulation stability of motors with different rotor flux linkages, the parameter values ​​of the power current limiting PI regulator are updated by the pump flux linkage and speed, as shown in the following formula: The temperature load limiting adjustment method of the control algorithm module uses current drop curve hysteresis adjustment. In this embodiment, the temperature limit range of the current drop curve is set to 85~95 degrees Celsius, and the temperature protection is set to 105 degrees Celsius. The temperature of the power device is sampled; if it is lower than the lower limit of the temperature limit range... At 85 degrees Celsius, the output current limit of the temperature limiting module is set to the maximum drive amplitude of the controller. 15 amps, exceeding the upper limit of the temperature range. Set the starting current amplitude at 95 degrees. 3 Amperes. The current limit within the temperature-limited range is set according to the following formula: In the formula The current temperature is sampled as the average value and compared with the previous temperature hysteresis average value. If the temperature is within the range of the previous hysteresis reference value, no adjustment is made. In this embodiment, the temperature hysteresis range is selected as 1 degree. If the temperature exceeds the hysteresis range, the current temperature is set as the previous hysteresis reference value, and the temperature limit current value is calculated using the above formula. The hysteresis method optimizes the adjustment of the load due to frequent fluctuations caused by temperature fluctuations.

[0038] The control method of this invention mainly covers a limiting factor algorithm module, a photovoltaic input adjustment module, and a permanent magnet synchronous motor drive module.

[0039] The aforementioned limiting factor algorithm module addresses the limitations imposed on the pump drive process by factors such as photovoltaic voltage input, controller temperature, motor power, and pump rated speed. This invention incorporates an input voltage loop PI regulator within the control algorithm framework. The limiting factors are identified through various internal regulators, yielding current limits for voltage utilization, power load reduction, temperature, and speed regulation. These current limits are then aggregated. The aggregated current limits are used to assign values ​​to the integral regulator amplitude limit and output reference current amplitude limit of the voltage loop PI regulator. This enables the control algorithm to respond to all limiting factors. The specific adjustment methods for each limiting factor are as follows: (1) Voltage utilization rate current limitation: The actual voltage utilization rate is limited by the current sampling time window of the control hardware through the current sampling resistor and the amplitude of the photovoltaic input voltage. The voltage utilization rate uses a PID regulator. The voltage utilization rate limiting module uses a PID regulator with the system-set voltage utilization rate as the input reference parameter, the current loop PI regulator output drive voltage as the feedback parameter, and the PID regulator outputs the voltage utilization rate limiting current.

[0040] (2) Temperature Limitation: In actual use, the controller implemented in this invention is affected by factors such as installation controls and sunlight exposure. Operating at full power above the set temperature can easily damage the control hardware. The temperature limiting module uses a current drop curve hysteresis adjustment, taking the system-set controller sampling temperature value as a feedback parameter, and obtaining it based on the temperature drop curve. The temperature limiting module outputs the current limit to the current limiting factor merging module.

[0041] (3) Motor power limitation: The actual operating power of the aeration pump needs to be limited during operation; excessive power output can easily damage the pump's mechanical components. The motor power limitation module uses a PI controller to set the maximum motor power as the input reference parameter. The average power of the permanent magnet synchronous motor during its cycle is calculated by combining the drive voltage generated by the PI controller in the current loop of the permanent magnet synchronous motor drive module with the drive current obtained from current sampling, and this average power is used as the feedback value input to the PI controller. The motor power limitation output current limit is then fed into the current limitation factor merging module.

[0042] (4) Speed ​​regulation current limit: The actual operating speed of the aeration pump needs to be limited during operation, as excessive power output can easily damage the pump's mechanical components. The motor power limiting module uses a PID controller with the system's maximum pump speed as the input reference parameter. The pump speed calculated by the rotor angle observer of the permanent magnet synchronous motor drive module is used as the feedback value input for the PI controller. The speed regulation limit output current limit is then incorporated into the current limiting factor merging module.

[0043] The photovoltaic input regulation module includes a photovoltaic regulation unit and an input voltage loop PI regulator. The photovoltaic regulation unit obtains the average power of the permanent magnet synchronous motor (PMSM) calculated by the PMSM drive module for each cycle, compares it with the average power obtained from the reference voltage value of the previous cycle, and calculates the next reference voltage value and step size. The input voltage loop PI regulator obtains the target reference voltage value given by the photovoltaic regulation as the PI reference input, uses the bus voltage sample value as the PI feedback value, and uses the merged current limit value as the integral regulator amplitude limit and output reference current amplitude of the voltage loop PI regulator. The regulator calculates the output reference current value as the current loop reference input of the PMSM module.

[0044] The permanent magnet synchronous motor drive module mainly consists of a rotor angle observer, a current loop PI regulator, an output dead-zone voltage compensation unit, a current acquisition unit, and a three-phase power drive unit. The oxygenation pump uses a permanent magnet synchronous motor for vector sensorless drive. The control algorithm acquires the amplitude signals of each phase of the current, the bus voltage, and the actual drive voltage after dead-zone compensation. The rotor angle observer then obtains the rotor electrical angle and speed values ​​of the permanent magnet synchronous motor. The current loop PI regulator responds to the reference value generated by the voltage loop PI regulator of the photovoltaic input regulation module and outputs the actual drive voltage of the motor. The output dead-zone voltage compensation obtains the three-phase drive voltage and the current system dead-zone configuration, and after compensation, obtains the actual drive voltage used. The compensated value is then attributed to the rotor angle observer to obtain higher-precision rotor position feedback during low-speed operation.

[0045] Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort should fall within the scope of protection of the present invention.

Claims

1. A method for driving and controlling an oxygenation water pump with photovoltaic input and no battery storage, characterized in that, Includes the following steps: Step 1: Obtain system parameters and perform power-on self-test. If the current photovoltaic panel voltage input meets the startup voltage, then start the subsequent process. Step 2: By gradually increasing the amplitude of the small pulse width voltage and detecting the response current and response voltage, the line resistance and line inductance of the oxygenation pump are calculated respectively. Based on the line inductance and line resistance, the discretization ratio and integral parameter values ​​of the current loop PI regulator are calculated. Step 3: Start the motor and gradually increase the frequency, detect the photovoltaic input voltage, motor drive voltage and load power, and switch to photovoltaic closed-loop control when the motor drive voltage reaches the voltage switching threshold; Step 4: The photovoltaic closed-loop control includes a limiting factor algorithm module, a photovoltaic input adjustment module, and a permanent magnet synchronous motor drive module. The permanent magnet synchronous motor drive module controls the vector drive of the permanent magnet synchronous motor, the photovoltaic input adjustment module tracks the maximum power point of the photovoltaic panel, and the limiting factor algorithm module responds to limiting factors.

2. The method for driving and controlling an oxygenation water pump with photovoltaic input and no battery storage as described in claim 1, characterized in that, In step 1, the input bus voltage is collected. When the voltage exceeds the low voltage protection voltage, the current sampling circuit signal reference is obtained. The average value after sampling is used to calculate the reference value. In order to avoid the error offset introduced by comparing the reference value obtained by the digital control power supply under photovoltaic low voltage with the actual working time.

3. The method for driving and controlling an oxygenation water pump with photovoltaic input and no battery storage as described in claim 1, characterized in that, In step 2, the calculation of the oxygenation pump line resistance includes: gradually increasing the amplitude of the small pulse width voltage until the current value to be responded to increases to the target current value and stabilizes within the threshold range, recording the current value and voltage value once, and calculating the pump line resistance based on the voltage value and current value recorded twice consecutively.

4. The method for driving and controlling an oxygenation water pump with photovoltaic input and no battery storage as described in claim 1, characterized in that, In step 2, the calculation of the oxygenation pump line inductance includes: applying a constant amplitude AC detection voltage stepwise with a fixed electrical angle; calculating the power factor parameter based on the response voltage, current amplitude, and cumulative power detection point value; and calculating the oxygenation pump line inductance based on the power factor parameter.

5. The method for driving and controlling an oxygenation water pump with photovoltaic input and no battery storage as described in claim 1, characterized in that, In step 3, the voltage switching threshold is 5V.

6. The method for driving and controlling an oxygenation water pump with photovoltaic input and no battery storage as described in claim 1, characterized in that, The limiting factors mentioned in step 4 include voltage utilization, controller temperature, oxygenation pump motor power, and oxygenation pump motor speed. The current limit values ​​corresponding to each limiting factor are integrated by the current limiting factor merging module to limit the integral regulator amplitude and output reference current amplitude of the voltage loop PI regulator.

7. The method for driving and controlling an oxygenation water pump with photovoltaic input and no battery storage as described in claim 1, characterized in that, In step 4, the photovoltaic input regulation module includes a photovoltaic regulation unit and an input voltage loop PI regulator.

8. The method for driving and controlling an oxygenation water pump with photovoltaic input and no battery storage as described in claim 1, characterized in that, In step 4, the permanent magnet synchronous motor drive module includes a rotor angle observer, a current loop PI regulator, an output dead zone voltage compensation unit, a current acquisition unit, and a three-phase power drive unit.

9. A hardware drive circuit for controlling a photovoltaic oxygenation water pump, characterized in that, include: Solar photovoltaic panels are used to power the oxygenation pump and digital control system. The DC bus is equipped with a support capacitor to provide drive power and buffer the motor start-up detection and closed-loop drive process; Storage chips are used to store system parameter configurations; The differential current sampling circuit sets the zero point of the current value corresponding to the non-zero reference value of the current sampling signal, and works in conjunction with voltage sampling to obtain operating parameters; The drive signal and sampling trigger module is used to generate power transistor switching signals based on drive voltage parameters; The inverter current sampling circuit uses a three-phase full-bridge drive circuit to output modulated drive based on the calculated voltage. The three-phase cable, with a variable length structure, connects the half-bridge output of the three-phase full-bridge circuit to the oxygenation pump load. The oxygenation pump is equipped with a built-in permanent magnet synchronous motor, which drives the pump head to operate. The current sampling resistor is connected to the drain of the lower power transistor in the three-phase full-bridge circuit. When the lower power transistor of the half-bridge is turned on, the current value is calculated based on the sampling trigger signal.

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