Motor driving device of photovoltaic deep-well pump

Abstract

The utility model provides a photovoltaic deep-well pump motor driving device, and relates to the technical field of deep-well pump motor driving. Comprising a motor driver which is arranged in an underground deep well, is connected with a motor and is used for driving the motor of the deep-well pump, a direct-current power supply device which is arranged on the ground, is connected with the motor driver and is used for providing a voltage-stabilized direct-current power supply for the motor driver, and a cable which is connected with the motor driver and the direct-current power supply device and is used for transmitting the direct-current power supply. According to the utility model, the direct-current power supply device which is arranged on the ground and is connected with the motor driver is adopted to output a voltage-stabilized direct-current power supply, the voltage-stabilized direct-current power supply is transmitted to the bus of the deep pump motor driver through the cable, the motor driver inverts bus direct current into alternating current to drive the motor to operate, and a rectifying circuit and a large-capacity electrolytic capacitor are not needed in the motor driver; the problems of vibration and heating of the motor during operation caused by waveform distortion due to long cable transmission of an inverter alternating current power supply are solved, so that normal operation of the deep-well pump motor is ensured.

Description

Technical Field

[0001] The utility model relates to the technical field of deep well pump motor drive, and particularly relates to a photovoltaic deep well pump motor drive device. Background Technique

[0002] The deep well pump motor works underground. Due to the water sources of groundwater in different regions, the well depth ranges from dozens of meters to hundreds of meters. The deep well pump motor needs cables of dozens of meters to hundreds of meters to work underwater.

[0003] The placement methods of the photovoltaic deep well pump motor driver are divided into two types: external and internal. Method 1: The "external" motor driver is placed on the well surface. The three-phase inverter AC power output by the driver reaches the deep well pump motor through a cable. The inverter AC power can only be used for cable transmission of dozens of meters. Long-distance transmission generates interference and waveform distortion, resulting in increased vibration and heating of the motor during operation. Method 2: The "internal" motor driver is placed underground, and the motor and the driver are integrated. The AC power supply method requires a rectifier circuit and a large-capacity electrolytic capacitor to maintain the stability of the DC bus voltage and provide working conditions for the normal operation of the motor.

[0004] The characteristics of electrolytic capacitors are large capacitance, large volume, and relatively short lifespan. They are one of the main components causing failures in motor drivers. The deep well pump motor is small in size and not easy to maintain, disassemble, and install, which is the main difficulty of the internal driver of the deep well pump motor.

[0005] In the prior art, it is realized by using a motor driver without electrolytic capacitors or with film capacitors. There are two specific implementation schemes: one is to increase a power decoupling circuit to suppress the fluctuation of the DC bus voltage (CN 115242103 A A non-electrolytic capacitor power converter for a permanent magnet synchronous motor); the other is to improve the control software algorithm to dynamically compensate the speed and torque of the motor and reduce the influence brought by the fluctuation of the bus voltage (CN 114301361 A A non-electrolytic capacitor permanent magnet based on bus current control).

[0006] The above two methods have the following disadvantages: For the first scheme of increasing the power decoupling circuit, components and installation space need to be added. For the second scheme of improving the control software algorithm, it is very complex and occupies the resources of the motor microprocessor, and the compensation for the bus voltage fluctuation is limited.

[0007] Based on this, this application is proposed. Content of the Utility Model

[0008] The utility model provides a photovoltaic deep well pump motor drive device to solve at least one problem in the background technique, enabling the cable to transmit DC power and ensuring the normal operation of the deep well pump motor.

[0009] To achieve the above object, the utility model provides the following technical solutions:

[0010] Photovoltaic deep well pump motor drive device, comprising:

[0011] A motor driver, placed in an underground deep well and connected to the motor, for driving the deep well pump motor;

[0012] A DC power supply device, placed on the ground and connected to the motor driver, for providing a regulated DC power supply to the motor driver;

[0013] A cable, connecting the motor driver and the DC power supply device, for transmitting the DC power supply.

[0014] The present utility model provides a preferred solution, wherein the motor driver does not have a regulated circuit electrolytic capacitor or capacitor, and the motor driver inversely outputs an AC source to drive the deep well pump motor to run at variable speed.

[0015] The present utility model provides a preferred solution, wherein the output end of the DC power supply device is provided with an electrolytic capacitor or capacitor whose total capacitance value matches the power of the motor driver, so as to stabilize the output DC voltage and compensate for the voltage drop fluctuation caused by the cable resistance.

[0016] The present utility model provides a preferred solution, wherein the output end of the DC power supply device is further provided with a discharge unit and a resistor connected to the discharge unit.

[0017] The present utility model provides a preferred solution, wherein the DC power supply device adopts a photovoltaic and complementary power supply device.

[0018] The present utility model provides a preferred solution, wherein the photovoltaic and complementary power supply device includes the commercial power, as one of the power supply inputs; a photovoltaic module, as one of the power supply inputs; a rectification module, whose input end is connected to the commercial power, for converting the alternating current of the commercial power into direct current; a complementary module, whose input ends are respectively connected to the output end of the rectification module and the output end of the photovoltaic module (solar panel), for enabling the photovoltaic module and the commercial power to compete and complement each other in power supply, and the output end of the complementary module outputs a DC power supply.

[0019] The present utility model provides a preferred solution, wherein the photovoltaic and complementary power supply device further includes a battery, as one of the power supply inputs; a bidirectional DC / DC module, bidirectionally connected to both the battery and the complementary module, on the one hand, for charging and storing the redundant electric energy of the complementary module to the battery, and on the other hand, for discharging the battery to supply power to the complementary module.

[0020] The present utility model provides a preferred solution, wherein the motor driver is installed on the deep well electric pump, that is, the motor driver and the deep well pump motor are integrated into one body, shortening the line length of the inverted AC power transmission.

[0021] Compared with the prior art, the above technical solution has the following advantages:

[0022] The motor drive device of the photovoltaic deep well pump of the present utility model uses a DC power supply device placed on the ground and connected to the motor driver to output a regulated DC voltage, which is transmitted to the bus of the deep well pump motor driver through a cable, that is, the cable transmits a regulated DC power supply. The motor driver inverses the DC on the bus into AC to drive the motor to operate, and there is no need for a rectifying circuit and large-capacity electrolytic capacitors in the motor driver, solving the problem of waveform distortion caused by the transmission of inverted AC power through a long cable, resulting in motor operation vibration and heating, and can ensure the normal operation of the deep well pump motor. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions in the embodiments of the present utility model or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only the embodiments of the present utility model. For those of ordinary skill in the art, other drawings can be obtained according to the provided drawings without creative efforts.

[0024] Figure 1 It is the circuit module block diagram of the photovoltaic deep well pump motor drive device provided in Embodiment 1 of the present utility model;

[0025] Figure 2 It is the circuit module block diagram of the photovoltaic deep well pump motor drive device provided in Embodiment 2 of the present utility model. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0026] The following will clearly and completely describe the technical solutions in the embodiments of the present utility model with reference to the drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all of the embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present utility model.

[0027] Embodiment 1

[0028] Please refer to Figure 1 , this embodiment provides a motor drive device for a photovoltaic deep well pump, including:

[0029] A motor driver, placed in an underground deep well and connected to the motor, for driving the deep well pump motor;

[0030] A DC power supply device, placed on the ground and connected to the motor driver, for providing a regulated DC power supply for the motor driver;

[0031] A cable, connecting the motor driver and the DC power supply device, for transmitting the DC power supply.

[0032] In this embodiment, the motor driver does not have an electrolytic capacitor or capacitor in the voltage stabilizing circuit. The DC power supply device adopts a photovoltaic and complementary power supply device, that is, an energy booster, and an electrolytic capacitor or capacitor with a total capacitance value matching the power of the motor driver is provided at the output end. The total capacitance value of the configured electrolytic capacitor is increased to 1 - 0.5 uF per watt of motor power to stabilize the bus voltage. The photovoltaic and complementary power supply device outputs a regulated DC power supply, which is transmitted through a cable and connected to the motor driver as the bus DC voltage of the motor driver. The motor driver inversely outputs an AC source to drive the deep well pump motor to run at variable speed, so that the DC voltage can be stably output to compensate for the voltage drop fluctuation caused by the cable resistance.

[0033] In this embodiment, a discharge unit is also provided at the output end of the DC power supply device (photovoltaic and complementary power supply device / energy booster), and a resistor connected to the discharge unit is connected to the DC bus.

[0034] In this embodiment, the motor driver is installed on the deep well pump, that is, the motor driver and the deep well pump motor are integrated into one body, shortening the line length of the inverted AC power transmission. The deep well pump has a cylindrical structure, with a multi-stage pump in the upper section, a motor in the middle section, and a driver in the lower section.

[0035] Through the solution of this embodiment, the voltage fluctuation of the motor driver bus can be effectively suppressed, thus meeting the usage environment requirements of the deep well pump motor load.

[0036] Embodiment 2

[0037] Please refer to Figure 2 , this embodiment provides a photovoltaic deep well pump motor drive device. The photovoltaic and complementary power supply device includes

[0038] Mains electricity, as one of the power supply inputs;

[0039] Photovoltaic modules, as one of the power supply inputs;

[0040] A rectification module, with its input end connected to the mains electricity, for converting the alternating current of the mains electricity into direct current;

[0041] A complementary module, with its input ends respectively connected to the output end of the rectification module and the output end of the photovoltaic module (solar panel), for enabling the photovoltaic module and the mains electricity to compete and supply power complementarily. The output end of the complementary module outputs a DC power supply.

[0042] The photovoltaic and complementary power supply device of this embodiment further includes

[0043] A battery, as one of the power supply inputs;

[0044] A bidirectional DC / DC module, which is bidirectionally connected to both the battery and the complementary module. On the one hand, it is used to charge the battery with the excess electrical energy from the complementary module for storage, and on the other hand, it is used to supply power to the complementary module by discharging the battery.

[0045] Specifically, the photoelectric complementary power supply device of this embodiment can adopt the patented technology of "a photoelectric complementary motor drive device" (publication number: CN 218940685). This patented photoelectric complementary motor drive device includes a solar power supply unit, a grid power supply unit, and a DC bus output. The power generated by the solar panels is boosted by a boost circuit and then connected to both ends of the DC bus output. The AC input is rectified by a rectifier circuit and then supplies power to the DC bus output. The DC bus output serves as the input for motor drive to supply power to the drive motor. For the specific scenarios of photoelectric competition and complementarity, as well as battery charging and discharging, refer to the solutions in this patent.

[0046] The photovoltaic deep well pump motor drive device provided in the above Embodiment 1 and Embodiment 2 can solve the problems in the prior art that the built-in motor drive controller, rectifier circuit, and electrolytic capacitor in the deep well pump make the deep well pump difficult to maintain in terms of lifespan and have a large size. Or it can solve the technical problems in the prior art that the external driver causes interference and waveform distortion during long-distance (tens to hundreds of meters) transmission of the inverter power supply, resulting in increased vibration and heating of the motor during operation. Specifically, the following beneficial technical effects can be achieved:

[0047] (1) The speed regulation operation of the deep well pump is widely used for its high efficiency and energy conservation. The photovoltaic power supply and AC / DC power supply complement each other to ensure that the deep well pump can supply water all day long. The photoelectric complementary motor drive device outputs a regulated DC voltage, which is transmitted to the bus of the deep well pump motor driver through a cable. There is no need for a rectifier circuit and a large-capacity electrolytic capacitor inside the motor driver. The motor driver inverses the DC on the bus into AC to drive the motor to operate.

[0048] (2) Move the rectifier circuit and the large-capacity aluminum electrolytic capacitor to the "photoelectric complementary motor drive device" end, and transmit the DC power supply through the cable, which solves the waveform distortion caused by long cable transmission of the inverted AC power supply, resulting in vibration and heating of the motor during operation.

[0049] (3) The outer diameter of the deep well pump motor is 60 - 150 mm, and the space for installing the built-in motor driver is very small. The rectifier circuit and the regulated electrolytic capacitor of the motor driver account for half of the volume of the driver. There is no need for a rectifier circuit and a large-capacity electrolytic capacitor inside the motor drive, and there is no need to install and expand the driver, making the driver small in size, easy to install, and easy to maintain.

[0050] (4) The service life of the electrolytic capacitor is related to the ambient temperature and the effective value of the charging current. The electrolytic capacitor is a vulnerable part in the frequency converter and needs to be checked and replaced regularly. The absence of electrolytic capacitors inside the motor drive improves the reliability of the deep well pump motor.

[0051] (5) For the photovoltaic deep well pump motor drive device of the present utility model, after boosting, the voltage is always higher than the voltage of the DC bus output.

[0052] In each embodiment described in this specification, the focus is on the differences from other embodiments. For the same or similar parts among the embodiments, reference can be made to each other.

[0053] The above has introduced in detail the photovoltaic deep well pump motor drive device provided by the present application. Specific examples are used in this article to elaborate on the principle and implementation manner of the present application. The description of the above embodiments is only used to help understand the method and its core idea of the present application. It should be noted that for those of ordinary skill in the art in this technical field, without departing from the principle of the present application, several improvements and modifications can be made to the present application, and these improvements and modifications also fall within the protection scope of the claims of the present application.

Claims

1. Photovoltaic deep well pump motor drive device, characterized in that, Comprising: A motor driver, placed in an underground deep well and connected to a motor, for driving a deep well pump motor; A DC power supply device, placed on the ground and connected to the motor driver, for providing a regulated DC power supply to the motor driver; A cable, connecting the motor driver and the DC power supply device, for transmitting the DC power supply.

2. The photovoltaic deep well pump motor drive device according to claim 1, wherein The motor driver does not have electrolytic capacitors or capacitors, and the motor driver outputs an inverted AC source to drive the deep well pump motor for speed regulation operation.

3. The photovoltaic deep well pump motor drive device according to claim 2, characterized in that The output end of the DC power supply device is provided with electrolytic capacitors or capacitors whose total capacitance value matches the power of the motor driver.

4. The photovoltaic deep well pump motor drive device according to claim 3, characterized in that, The output end of the DC power supply device is also provided with a discharge unit and a resistor connected to the discharge unit.

5. The photovoltaic deep well pump motor drive device according to any one of claims 1 to 4, characterized in that, The DC power supply device uses a photovoltaic and complementary power supply device.

6. The photovoltaic deep well pump motor drive device according to claim 5, characterized in that, The photovoltaic and complementary power supply device includes Mains electricity, as one of the power supply inputs; Photovoltaic modules, as one of the power supply inputs; A rectification module, with its input end connected to the mains electricity, for converting the alternating current of the mains electricity into direct current; A complementary module, with its input ends respectively connected to the output end of the rectification module and the output end of the photovoltaic modules, for enabling the photovoltaic modules and the mains electricity to compete and complement each other in power supply, and the output end of the complementary module outputs a DC power supply.

7. The photovoltaic deep well pump motor drive device according to claim 6, characterized in that, The photovoltaic and complementary power supply device also includes A battery, as one of the power supply inputs; A bidirectional DC / DC module, bidirectionally connected to both the battery and the complementary module, on the one hand for charging and storing the excess electrical energy from the complementary module to the battery, and on the other hand for discharging the battery to supply power to the complementary module.

8. The photovoltaic deep well pump motor drive device according to any one of claims 1 to 4, characterized in that, The motor driver is installed on the deep well pump.

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