CN114915247A - Motor driving system and method for tracking photovoltaic power station - Google Patents

Abstract

The invention discloses a motor driving system and a method for tracking a photovoltaic power station, the system comprises a main control box and at least one motor driving module, the main control box is in communication connection with the motor driving module through a power carrier mode and provides power supply, the motor driving module is arranged in a motor and comprises a power carrier demodulation circuit, a driving circuit and an MCU circuit, the power carrier demodulation circuit is used for demodulating an instruction signal loaded on a power line of the main control box and transmitting the instruction signal to the MCU circuit, the MCU circuit generates a first driving signal according to the demodulated instruction signal and transmits the first driving signal to the driving circuit to control the operation of the motor, the driving circuit is used for collecting a detection signal generated in the operation process of the motor and transmitting the detection signal to the MCU circuit, the MCU circuit generates a state signal according to the detection signal, and the state signal comprises the position of the motor, and generating a second driving signal according to the position of the motor and sending the second driving signal to the driving circuit to control the motor to operate. The invention can save the cost of the cable and avoid signal interference.

Description

Motor driving system and method for tracking photovoltaic power station

Technical Field

The invention relates to the field of photovoltaic control, in particular to a motor driving system and a motor driving method for a tracking photovoltaic power station.

Background

The photovoltaic power station is composed of a plurality of photovoltaic power generation devices, in order to improve the power generation efficiency, an adjustable component support capable of rotating around a rotating shaft is generally adopted to install a photovoltaic component, and a motor is adopted to drive the rotating shaft to rotate to adjust the angle. A plurality of motors are installed on the adjustable subassembly support to be connected with the main control box, the main control box is connected with the motor and adopts communication cable and power cord to carry out communication connection and power connection respectively usually, because the main control box need carry out communication connection respectively with a plurality of motors, consequently need adopt a large amount of communication cables, thereby produce a large amount of communication cable's cost and lay the cost. Referring to fig. 1, the existing tracking photovoltaic power station motor driving module is arranged in a main control box and is connected with a motor through a driving cable and a hall signal cable, and the cable is high in cost, large in laying difficulty and high in cost.

Present photovoltaic power plant has a large amount of communication cables to cause cost pressure, and the brush motor that current tracking photovoltaic power plant adopted is short-lived, and power plant later maintenance is with high costs, and the degree of difficulty is big, adopts long cable transmission hall signal to receive easily in the motor to disturb and lead to serious distortion in addition to hall signal transmission distance is short, leads to control box and motor to place the position limited.

Disclosure of Invention

In view of the technical problems mentioned in the background art, embodiments of the present application provide a motor driving system and method for tracking a photovoltaic power station to solve the above problems.

The embodiment of the application provides a motor driving system of a tracking photovoltaic power station, which comprises a main control box and at least one motor driving module, wherein the main control box is in communication connection with the motor driving module in a power carrier mode and supplies power, the motor driving module is arranged in a motor and comprises a power carrier demodulation circuit, a driving circuit and an MCU circuit, the power carrier demodulation circuit is used for demodulating an instruction signal loaded on a power line of the main control box and sending the demodulated instruction signal to the MCU circuit, the MCU circuit generates a first driving signal according to the demodulated instruction signal and sends the first driving signal to the driving circuit so as to control the operation of the motor, the driving circuit is used for acquiring a detection signal generated in the operation process of the motor and sending the detection signal to the MCU circuit, the MCU circuit is used for generating a state signal according to the detection signal, and the state signal comprises the position of the motor, the MCU circuit generates a second driving signal according to the position of the motor and sends the second driving signal to the driving circuit so as to control the operation of the motor, and the power carrier demodulation circuit is used for loading a state signal generated on the MCU circuit on a power line and sending the state signal to the main control box.

Preferably, the MCU circuit calculates the position of the motor in a high-frequency injection mode in the starting stage of the motor, and calculates the position of the motor in a back electromotive force zero-crossing detection mode in stable running.

Preferably, the MCU circuit carries out limit detection according to the position of the motor, if the position of the motor does not reach the limit position, the motor is operated to the target position, whether the motor is operated to the target position is detected, if the motor is operated to the target position, the motor is controlled to stop operating, otherwise, the motor is continuously driven to rotate until the motor reaches the target position, and if the position of the motor reaches the limit position, the motor is controlled to stop operating.

Preferably, the power supply further comprises a power supply protection circuit, a voltage and current acquisition circuit and a voltage and current comparison circuit, the power supply is connected and then sequentially supplies power to the driving circuit through the power supply protection circuit and the power carrier demodulation circuit, the voltage and current acquisition circuit is used for acquiring current signals of the driving circuit, the voltage and current acquisition circuit generates level signals according to the current signals of the driving circuit and respectively sends the generated level signals to the MCU circuit and the voltage and current comparison circuit, the MCU circuit analyzes the grid drive reversing sequence according to the level signals and respectively outputs high and low levels to the power supply protection circuit according to the level signals with the voltage and current comparison circuit so as to control the on and off of the power supply.

Preferably, the motor driving module is a single chip microcomputer.

Preferably, the temperature control circuit further comprises a temperature acquisition circuit, the temperature acquisition circuit is used for sending the real-time temperature of the driving circuit to the MCU circuit, and the MCU circuit carries out over-temperature judgment and controls the motor to operate according to a judgment result.

Preferably, the drive circuit further comprises a burn-in prevention circuit, and the burn-in prevention circuit is used for protecting the drive circuit.

Preferably, the rated voltage range of the power protection circuit is 12V to 48V, the maximum voltage is 60V, and the maximum current is 10A.

Preferably, the command signal and the status signal are TTL signals, the command signal includes starting, stopping, forward rotation, reverse rotation, acceleration, deceleration and/or operation of the motor to a specific position, and the status signal includes a current position of the motor, an accumulated pulse number, a synchronization condition, a fault condition and/or whether or not the voltage and current are normal.

Preferably, the motor is a brushless motor and the drive circuit is a three-phase half-bridge drive circuit.

Preferably, the motor is a brush motor, and the drive circuit is an H-bridge drive circuit.

The application also provides a motor driving method of the tracking photovoltaic power station, and the motor driving system of the tracking photovoltaic power station comprises the following steps:

s1, acquiring and demodulating the command signal loaded on the power line of the main control box in a power carrier mode to obtain a demodulated command signal;

s2, generating a first driving signal according to the demodulated command signal and controlling the motor to operate according to the first driving signal;

s3, acquiring a detection signal generated in the running process of the motor, generating a state signal according to the detection signal, wherein the state signal comprises the position of the motor, generating a second driving signal according to the position of the motor and controlling the motor to run according to the second driving signal;

and S4, loading the state signal on the power line and sending the state signal to the main control box in a power carrier wave mode.

Compared with the prior art, the invention has the following beneficial effects:

(1) the motor driving module and the main control box are connected and communicated in a Power Line Carrier (PLC) mode, a Hall signal line is omitted, cost can be effectively reduced, and communication signals are interacted on a 48V power supply cable, so that a large amount of communication cable cost and laying cost can be saved.

(2) The invention separates the main control box from the motor driving module, and the motor driving module is arranged in the motor, thereby increasing the transmission distance and flexibly designing the placing positions of the main control box and the motor.

(3) The motor driving module of the motor driving system of the tracking photovoltaic power station can process various signals in the motor, avoids the problems of serious distortion and the like caused by the driving interference generated by the Hall signal of the motor under the condition of a long cable, and can thoroughly solve the problem that the interference signal generated by the driving influences a main control box.

Drawings

The accompanying drawings are included to provide a further understanding of the embodiments and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments and together with the description serve to explain the principles of the invention. Other embodiments and many of the intended advantages of embodiments will be readily appreciated as they become better understood by reference to the following detailed description. The elements of the drawings are not necessarily to scale relative to each other. Like reference numerals designate corresponding similar parts.

FIG. 1 is a schematic diagram of a prior art motor drive system for tracking a photovoltaic power plant;

FIG. 2 is a schematic diagram of a communication connection of a motor drive system of a tracking photovoltaic power plant of an embodiment of the present application;

FIG. 3 is a schematic diagram of a motor drive module of a motor drive system of a tracking photovoltaic power plant of an embodiment of the present application;

FIG. 4 is a schematic diagram of a burn tube prevention circuit of a motor drive system of a tracking photovoltaic power plant of an embodiment of the present application;

FIG. 5 is a logic schematic of a motor drive module controlling a motor of a motor drive system of a tracking photovoltaic power plant of an embodiment of the present application;

FIG. 6 is a schematic diagram of a voltage current acquisition circuit and a voltage current comparison circuit of a motor drive system of a tracking photovoltaic power plant of an embodiment of the present application;

FIG. 7 is a schematic diagram of a power protection circuit of a motor drive system of a tracking photovoltaic power plant of an embodiment of the present application;

FIG. 8 is a schematic diagram of a power carrier demodulation circuit of a motor drive system of a tracking photovoltaic power plant of an embodiment of the present application;

FIG. 9 is a schematic diagram of an MCU circuit of a motor drive system of a tracking photovoltaic power plant of an embodiment of the present application;

FIG. 10 is a schematic diagram of a drive circuit of a motor drive system of a tracking photovoltaic power plant of an embodiment of the present application;

FIG. 11 is a schematic diagram of the circuitry of the back EMF signal detection portion of the MCU circuitry of the motor drive system of the tracking photovoltaic power plant of an embodiment of the present application;

FIG. 12 is a schematic diagram of a temperature acquisition circuit of a motor drive system of a tracking photovoltaic power plant of an embodiment of the present application;

reference numerals: 1. a main control box; 2. a motor drive module; 3. a power carrier demodulation circuit; 4. a drive circuit; 5. an MCU circuit; 6. a power supply protection circuit; 7. a voltage current acquisition circuit; 8. a voltage-current comparison circuit; 9. a burn-in prevention circuit; 10. and a temperature acquisition circuit.

Detailed Description

The present application will be described in further detail with reference to the following drawings and examples. It is to be understood that the specific embodiments described herein are merely illustrative of the relevant invention and not restrictive of the invention. It should be noted that, for convenience of description, only the portions related to the related invention are shown in the drawings.

It should be noted that the embodiments and features of the embodiments in the present application may be combined with each other without conflict. The present application will be described in detail below with reference to the embodiments with reference to the attached drawings.

Referring to fig. 2 and 3, in an embodiment of the present invention, a motor driving system for tracking a photovoltaic power station is provided, including a main control box 1 and at least one motor driving module 2, where the main control box 1 is in communication connection with the at least one motor driving module 2 in a power carrier manner and provides power, the main control box 1 and the motor are two separate parts, the motor driving module 2 is embedded in the motor, and in a specific embodiment, the motor driving module 2 is a single chip microcomputer. The motor driving module 2 comprises a power carrier demodulation circuit 3, a driving circuit 4, an MCU circuit 5, a power supply protection circuit 6, a voltage and current acquisition circuit 7, a voltage and current comparison circuit 8, a burning prevention circuit 9 and a temperature acquisition circuit 10, wherein the power carrier demodulation circuit 3 is used for demodulating a command signal loaded on a power line of the main control box 1 and sending the demodulated command signal to the MCU circuit 5, the MCU circuit 5 generates a first driving signal according to the demodulated command signal and sends the first driving signal to the driving circuit 4 to control the operation of the motor, after the motor operates, the driving circuit 4 is used for acquiring a detection signal and sending the detection signal to the MCU circuit 5, the MCU circuit 5 is used for generating a state signal according to the detection signal, and the detection signal is a signal detected by the driving circuit in the operation process of the motor, such as a counter electromotive force signal detected in a counter electromotive force zero crossing detection mode, the state signal comprises the position of the motor, the MCU circuit 5 generates a second driving signal according to the position of the motor and sends the second driving signal to the driving circuit 4 to control the operation of the motor, and the power carrier demodulation circuit 3 is used for loading the state signal generated on the MCU circuit 5 on a power line and sending the state signal to the main control box 1. In a specific embodiment, the main control box 1 is located in the control box, the motor driving modules are located in the motor internal driving board and serve as slave controllers, therefore, the main control box 1 is responsible for communicating with each motor driving module 2, and the motor driving modules 2 are responsible for receiving command signals and uploading state signals of the motor driving modules to the main control box 1, so that the configuration of one master and multiple slaves is more flexible, and the number of the slaves can reach 256 theoretically. The instruction signal and the state signal are TTL signals, the instruction signal comprises starting, stopping, forward rotation, reverse rotation, acceleration, deceleration and/or operation of the motor to a specific position, and the state signal comprises the current position, accumulated pulse number, synchronization condition, fault condition and/or whether voltage and current are normal or not. The main control box 1 provides communication and power supply through a plurality of two-core cables and a plurality of motors, the outside provides a PLC interface, and the motor driving module 2 is arranged in the motor and used for processing communication and controlling the motor. Separate main control box 1 and motor drive module 2, motor drive module 2 can be at the inside various signals of processing of motor, consequently can avoid conducting interference signal to main control box 1 to influence the operation of main control box end. When the wind load is small, the main control box 1 synchronously drives a plurality of motors, and the power meets the requirement at the moment; when the wind load is large, the main control box 1 drives a plurality of motors in a staggered mode, namely the motors alternately run at a minimum angle, and the power requirement is guaranteed.

In a specific embodiment, the motor driving module 2 is responsible for processing data as a master chip. The motor driving module 2 integrates a power supply protection circuit 6, a power carrier demodulation circuit 3, a burning-proof circuit 9, a driving circuit 4, a voltage and current acquisition circuit 7, a voltage and current comparison circuit 8 and a temperature acquisition circuit 10. The power protection circuit 6 has the functions of preventing reverse protection, overvoltage protection and overcurrent protection of the power supply. The power carrier demodulation circuit 3 is used for resolving command signals sent by the main control box 1 from a power line. Referring to fig. 4, the burn-in prevention circuit 9 is used to protect the driving circuit 4, and the circuit is used to ensure that the input levels of the high side and the low side of the gate driving are not consistent, and prevent the NMOS of the upper arm and the lower arm of the three-phase bridge of the driving circuit 4 from being turned on and burned out. In the aspect of power supply, a 48V cable at the end of the main control box is adopted for transmission, and meanwhile, communication signals are loaded on a power supply line. The driving circuit 4 is used as a main circuit of the motor drive and is used for receiving a driving signal of the MCU circuit 5 and controlling the motor according to the driving signal, the voltage and current acquisition circuit 7 is used for acquiring phase voltage and phase current signals, and the voltage and current comparison circuit 8 outputs high and low levels according to the acquired current signals to control the power supply protection circuit 6 and simultaneously control the on-off of the power supply.

Referring to fig. 5, after receiving an instruction signal from the main control box 1, the power carrier demodulation circuit 3 is used to demodulate the instruction signal, the MCU circuit 5 determines whether the motor needs to operate according to the demodulated instruction signal, if the motor needs to operate, a first driving signal is generated and sent to the driving circuit 4 to control the operation of the motor, the voltage and current acquisition circuit 7 acquires current information during the operation of the motor, and determines whether the current exceeds the maximum current through the voltage and current comparison circuit 8, if the current exceeds the maximum current, the power protection circuit 6 performs overcurrent protection, if the current does not exceed the maximum current, the driving circuit 4 acquires position information of the motor and sends the position information to the MCU circuit 5, the MCU circuit 5 performs limit detection according to the position of the motor, if the position of the motor does not reach the limit position, the motor is operated to the target position, and whether the motor operates to the target position is detected, if the motor runs to the target position, the motor is controlled to stop running, if the motor does not run to the target position, the MCU circuit 5 generates a second driving signal to control the motor to run to the target position, and if the position of the motor reaches a limiting position, the motor is controlled to stop running. The motor can also be controlled to run in reverse at this time to avoid exceeding the stroke. The target position is a position where the motor is controlled to reach according to the command signal of the main control box 1. In the embodiment of the application, in addition to the overcurrent protection, overvoltage protection can be realized, only the flow of the overcurrent protection is given in fig. 5, and the flow of the overvoltage protection is also similar, which is not described herein again. Specifically, referring to fig. 6, the left side of fig. 6 shows that the voltage and current acquisition circuit 7 adopts an operational amplifier circuit to convert the current into a voltage signal of 0-3.3V and transmit the voltage signal to the MCU circuit 5, and the right side of fig. 6 shows that the voltage signal is compared with a reference voltage by the voltage and current comparison circuit 8 to determine whether the current exceeds the current threshold. For example: when the current exceeds the maximum power of the power supply, the current threshold is 10A, the system normally works within the current 10A, and the power supply is cut off when the current exceeds 10A. In a specific embodiment, referring to fig. 3, after a 48V power supply is connected, a command signal loaded at the end of the main control box 1 is also on the 48V power supply line, waveforms on the power supply line are square waves with different duty ratios, which represent different command signals, the motor driving module 2 receives and extracts the command signal therein, and similarly, the motor driving module 2 loads a self-state signal on the power supply line in the same manner and transmits the self-state signal to the main control box 1. Firstly, the power supply protection circuit 6 and the power carrier demodulation circuit 3 are used for supplying power to the drive circuit 4, and meanwhile, the power carrier demodulation circuit 3 is in communication connection with the MCU circuit 5, so that a demodulated instruction signal can be sent to the MCU circuit 5. MCU circuit 5 is further connected with drive circuit 4, not only can send drive signal to drive circuit 4 with control motor operation, can also send the detected signal that drive circuit 4 gathered to MCU circuit 5. The voltage and current acquisition circuit 7 is used for acquiring current signals of the driving circuit 4, the voltage and current acquisition circuit 7 generates level signals according to the current signals of the driving circuit 4, the generated level signals are respectively sent to the MCU circuit 5 and the voltage and current comparison circuit 8, the MCU circuit 5 analyzes a grid drive reversing sequence according to the level signals and outputs high and low levels to the power protection circuit 6 according to the level signals so as to control the switch of the power supply, in addition, the voltage and current comparison circuit 8 also outputs the high and low levels to the power protection circuit 6 according to the level signals so as to control the switch of the power supply, and both can realize the protection of the power supply. When the voltage and/or current exceeds the set threshold, the voltage-current comparison circuit 8 will output a high level to the switch circuit of the power supply part, thereby cutting off the power supply in time and stopping the system until the fault is relieved. Specifically, referring to fig. 7, the rated voltage range of the power protection circuit 6 is 12V to 48V, the maximum voltage is 60V, the maximum current is 10A, the reverse connection prevention function is provided, and the slow start time is 335 ms. Fig. 8 shows a circuit of the power carrier demodulation circuit 3.

Specifically, the MCU circuit 5 sends a driving signal to the driving circuit 4, the driving circuit 4 outputs a control signal to the motor according to the driving signal to control the motor to rotate or stop, the motor needs to pass through 6 stages during one rotation cycle, each stage has only two phases working, the other phase is in a power-off state, the MCU circuit 5 needs to output different driving signals to complete the 6 stages, i.e. a commutation sequence is generated, the current stage of the motor can be determined by detecting the magnitude and direction of the current, after determining the current stage of the motor, the MCU circuit 5 will output the driving signal of the next stage, and go back and forth, the current angle of the rotor is estimated by detecting the back electromotive force signal, the position of the motor is obtained, and the purpose of feeding back whether the MCU circuit 5 completes driving or not is achieved by comparing the position of the motor with the target position of the motor. If the voltage exceeds 60V (the voltage limit of the motor is 48V) or the current exceeds 10A, the voltage and current comparison circuit 8 is triggered to output high level, so that a switch circuit of a power supply part is controlled, a power supply path PMOS is cut off, the system is powered off, and the effect of protecting the power supply circuit is achieved.

In a specific embodiment, referring to fig. 9, the MCU circuit 5 uses an STM32F030R8 chip as a processing chip, wherein the timer IO outputs a gate driving signal, and in other alternative embodiments, the MCU circuit 5 may also use other types or models of chips. In one embodiment, the MCU circuit 5 calculates the position of the motor by high frequency injection during the starting phase of the motor, and calculates the position of the motor by back electromotive force zero-crossing detection during smooth operation. Specifically, one revolution of the motor is 0-360 degrees corresponding to one electric cycle, and each phase in the ABC three phases has two zero-crossing points in one electric cycle, so that one electric cycle is uniformly divided into 6 equal electric cyclesAnd 60 degrees, the angle of the rotor, namely the position of the motor can be obtained by detecting the waveform of the three-phase back electromotive force signal. In other alternative embodiments, the MCU circuit 5 may also acquire the position of the motor by reading hall signals, and specifically select a suitable manner for calculating the position of the motor according to the type of the motor. Specifically, as shown in fig. 10, which is a schematic diagram of the U-phase driver circuit 4, the V-phase and W-phase circuits remain identical, and the two LEDs indicate the gate drive high and low side signal states. The control mode of the motor adopts FOC closed-loop control. As shown in fig. 11, the counter electromotive force detecting portion of the driving circuit 4 is used for detecting zero-crossing of the center point of three phases, each phase has 2 counter electromotive force zero-crossing points in one rotation of the motor, and 6 counter electromotive force zero-crossing points in one rotation calculate the position of the motor by this rule, and the counter electromotive force of the a phase is calculated by the formula

Wherein V _A 、V _B 、V _C Referring to the terminal voltage of each phase, the back electromotive force of the B phase is calculated by the formula

The counter electromotive force of the C phase is calculated by the formula

The equation is zero, i.e., the zero crossing time of each phase.

In a specific embodiment, the temperature acquisition circuit 10 is configured to send the real-time temperature of the driving circuit 4 to the MCU circuit 5, and the MCU circuit 5 performs over-temperature judgment and controls the motor to operate according to the judgment result. The temperature acquisition circuit 10 can transmit the real-time temperature of the drive circuit 4 to the MCU circuit 5, which is beneficial to the MCU circuit 5 to carry out over-temperature judgment, and when the short circuit or the overcurrent abnormal condition occurs, the motor drive module 2 can be caused to rapidly heat up, thereby burning out the circuit or the motor, and when the MCU circuit 5 detects that the temperature exceeds the set threshold value, the motor can be stopped in time. Specifically, referring to fig. 12, the temperature acquisition circuit 10 employs a 10K NTC resistor to output different voltage values at different temperatures through voltage followers.

In a specific embodiment, the motor is a brushless motor, the driving circuit 4 is a three-phase half-bridge driving circuit, and the driving circuit 4 is formed by a high-side gate driver and a low-side gate driver of the english-flying-ice and 6 MOS transistors. Compared with a brush motor which is used in large quantity at present, the brushless motor has the advantages of low noise, stable operation, long service life, low failure rate and low later maintenance cost. In another embodiment, the motor is a brush motor, the driving circuit 4 is an H-bridge driving circuit, and 4 MOS transistors are used.

Corresponding to the above motor driving system for tracking a photovoltaic power station, an embodiment of the present application further provides a motor driving method for tracking a photovoltaic power station, including the following steps:

s1, acquiring and demodulating the command signal loaded on the power line of the main control box 1 in a power carrier mode to obtain a demodulated command signal;

s2, generating a first driving signal according to the demodulated command signal and controlling the motor to operate according to the first driving signal;

s3, acquiring a detection signal generated in the running process of the motor, generating a state signal according to the detection signal, wherein the state signal comprises the position of the motor, generating a second driving signal according to the position of the motor and controlling the motor to run according to the second driving signal;

s4, the status signal is applied to the power supply line and transmitted to the main control box 1 by means of power carrier.

According to the motor driving system and the motor driving method for the tracking photovoltaic power station, the communication between the main control box 1 and the motor driving module 2 is achieved in a power carrier mode, and the cost of communication cables and the laying cost are saved. When the motor is installed on the photovoltaic support in a rotating mode, cables needing to be used are long, so that the communication cables can be effectively saved by the aid of the motor driving system of the tracking photovoltaic power station, and the total cost of the cables is greatly reduced. The utility model provides a track photovoltaic power plant's motor drive system main control box 1 and motor drive module 2 of embodiment divide into solitary two parts, can handle various signals in motor drive module 2, avoid the drive to disturb and influence main control box 1.

While the present invention has been described with reference to the preferred embodiments, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention as defined by the appended claims. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

In the description of the present application, it is to be understood that the terms "upper", "lower", "inner", "outer", and the like, indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, are only for convenience in describing the present application and simplifying the description, and do not indicate or imply that the referred devices or elements must have a specific orientation, be constructed in a specific orientation, and be operated, and thus, should not be construed as limiting the present application. The word 'comprising' does not exclude the presence of elements or steps not listed in a claim. The word "a" or "an" preceding an element does not exclude the presence of a plurality of such elements. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage. Any reference signs in the claims shall not be construed as limiting the scope.

Claims (12)

1. A motor driving system for tracking a photovoltaic power station is characterized by comprising a main control box and at least one motor driving module, wherein the main control box is in communication connection with the motor driving module in a power carrier mode and supplies power, the motor driving module is arranged in a motor and comprises a power carrier demodulation circuit, a driving circuit and an MCU circuit, the power carrier demodulation circuit is used for demodulating an instruction signal loaded on a power line of the main control box and sending the demodulated instruction signal to the MCU circuit, the MCU circuit generates a first driving signal according to the demodulated instruction signal and sends the first driving signal to the driving circuit so as to control the operation of the motor, the driving circuit is used for acquiring a detection signal generated in the operation process of the motor and sending the detection signal to the MCU circuit, the MCU circuit is used for generating a state signal according to the detection signal, the state signal comprises the position of the motor, the MCU circuit generates a second driving signal according to the position of the motor and sends the second driving signal to the driving circuit to control the operation of the motor, and the power carrier demodulation circuit is used for loading the state signal generated on the MCU circuit on a power line and sending the state signal to the main control box.

2. The motor drive system of tracking photovoltaic power plants of claim 1 wherein the MCU circuit calculates the position of the motor during startup by high frequency injection and during steady operation by back emf zero crossing detection.

3. The system of claim 1, wherein the MCU circuit performs a limit detection based on the position of the motor, and if the position of the motor does not reach a limit position, the motor is operated to a target position, and whether the motor is operated to the target position is detected, and if the motor is operated to the target position, the motor is controlled to stop operating, otherwise the motor is continuously driven until the target position is reached, and if the position of the motor reaches a limit position, the motor is controlled to stop operating.

4. The motor driving system for tracking the photovoltaic power station as recited in claim 1, further comprising a power protection circuit, a voltage-current collection circuit and a voltage-current comparison circuit, wherein the power protection circuit and the power carrier demodulation circuit are sequentially connected to supply power to the driving circuit, the voltage-current collection circuit is configured to collect current signals of the driving circuit, the voltage-current collection circuit generates level signals according to the current signals of the driving circuit, and respectively sends the generated level signals to the MCU circuit and the voltage-current comparison circuit, the MCU circuit analyzes a gate drive commutation sequence according to the level signals, and outputs high and low levels to the power protection circuit according to the level signals with the voltage-current comparison circuit to control the switching of the power supply.

5. The motor drive system of tracking photovoltaic power plants of claim 1 wherein said motor drive module is a single chip.

6. The motor driving system of the tracking photovoltaic power plant of claim 1, further comprising a temperature acquisition circuit for sending real-time temperature of the driving circuit to the MCU circuit, the MCU circuit performing over-temperature determination and controlling the operation of the motor according to the determination.

7. The motor drive system of tracking photovoltaic power plant of claim 1 further comprising a burn-in protection circuit for protecting the drive circuit.

8. The motor drive system of tracking photovoltaic power plants of claim 4 characterized in that the rated voltage range of the power protection circuit is 12V-48V, the maximum voltage is 60V and the maximum current is 10A.

9. The motor drive system of a tracking photovoltaic power plant of claim 1 characterized in that the command signals and the status signals are TTL signals, the command signals include start, stop, forward rotation, reverse rotation, acceleration, deceleration and/or operation of the motor to a specific position, the status signals include the current position of the motor, accumulated number of pulses, synchronization condition, fault condition and/or whether voltage and current are normal.

10. The motor drive system of a tracking photovoltaic power plant of any of claims 1-9 characterized in that the motor is a brushless motor and the drive circuit is a three phase half bridge drive circuit.

11. The motor drive system of the tracking photovoltaic power plant of any of the claims 1 to 9 characterized in that the motor is a brushed motor and the drive circuit is an H-bridge drive circuit.

12. A motor driving method of a tracking photovoltaic power plant, characterized in that the motor driving system of a tracking photovoltaic power plant according to any one of claims 1 to 11 is employed, comprising the steps of:

s1, acquiring and demodulating the command signal loaded on the power line of the main control box in a power carrier mode to obtain a demodulated command signal;

s2, generating a first driving signal according to the demodulated command signal and controlling the motor to operate according to the first driving signal;

s3, acquiring a detection signal generated in the running process of the motor, generating a state signal according to the detection signal, wherein the state signal comprises the position of the motor, generating a second driving signal according to the position of the motor and controlling the motor to run according to the second driving signal;

and S4, loading the state signal on a power line and sending the state signal to the main control box in a power carrier mode.

Images