CN105048893B - Method for long-distance speed regulation of DC brushless motor - Google Patents

Abstract

A method for long-distance speed regulation of a DC brushless motor is realized by a device composed of a rectification control unit and a speed regulation unit. The rectification control unit inputs a single-phase 220V AC power supply, outputs a controllable rectification voltage stepped down by a transformer, and sends a speed control signal including the motor running direction and running speed level in the controllable rectification voltage; the speed control signal includes The guide wave composed of frequency cycle rectification wave and AC wave of 1 power frequency cycle and the data wave composed of multiple power frequency cycles; the speed adjustment unit inputs the controllable rectification voltage containing speed control signal to control the speed of brushless DC motor. The method does not need a remote controller, does not need to lay a separate control line, and directly uses a single-phase power line to transmit a speed control signal, which can realize the control and adjustment of the speed of the long-distance brushless DC motor.

Description

A method for long-distance speed regulation of DC brushless motor

technical field

The invention relates to a motor speed regulation technology, in particular to a method for long-distance speed regulation of a DC brushless motor.

Background technique

When it is necessary to remotely control and adjust the speed of the brushless DC motor, the usual methods are:

One is to use remote control. The drive control circuit of the brushless DC motor is equipped with a remote control receiving device, and the brushless DC motor can be adjusted stepwise or steplessly through the remote control. The disadvantage is that it needs to be equipped with a remote control, which is troublesome to manage easy to lose.

The second is the use of digital control technology. For example, the RS-485 bus is used to control the speed of the DC brushless motor. This solution is advanced in technology, but the cost is high. In addition to power lines, the system also needs to lay out digital control buses.

The third is to use analog signal control technology. For example, speed control using a remote potentiometer is less costly. But this method also needs to increase the control line, and the anti-interference ability is poor.

Contents of the invention

The purpose of the present invention is to provide a method for realizing long-distance speed regulation of a DC brushless motor by using a single-phase power line without adding control signal lines and without using a remote controller.

For achieving the above object, the technical scheme that the present invention takes is:

A method for long-distance speed regulation of a DC brushless motor is realized by a device composed of a rectification control unit and a speed regulation unit.

The rectification control unit is provided with a phase line input terminal, a neutral line input terminal, a first controllable rectification output terminal, and a second controllable rectification output terminal; the phase line input terminal and the neutral line input terminal are input to a single-phase 220V AC power supply ; The first controllable rectification output terminal and the second controllable rectification output terminal output a controllable rectification voltage.

The speed adjustment unit is provided with a first controllable rectification input terminal and a second controllable rectification input terminal, and the first controllable rectification input terminal and the second controllable rectification input terminal are respectively connected to the first controllable rectification input terminal of the rectification control unit. Controlled rectification output terminal, second controllable rectification output terminal.

The rectification control unit is composed of a transformer, a control power supply module, a controllable rectification module, a zero-crossing detection module, a single-chip microcomputer control module, a trigger control module, and a speed setting module.

The two input terminals of the transformer are the phase line input terminal and the neutral line input terminal respectively, and the two output terminals are respectively the first AC terminal and the second AC terminal; the first AC terminal and the second AC terminal output the second AC power.

The control power supply module is composed of a control power supply single-phase rectifier bridge and a first filtering and stabilizing circuit, and outputs a first DC working power supply; the two AC input ends of the control power supply single-phase rectifier bridge are respectively connected to the first AC terminal , the second AC terminal; the rectified negative terminal of the single-phase rectifier bridge of the control power supply is the common ground. The first DC working power outputted by the control power supply module supplies power to the single-chip microcomputer control module.

The controllable rectification module is composed of a rectifier bridge UR1, a bidirectional thyristor V1, a bidirectional thyristor V2, a bidirectional thyristor V3, and a bidirectional thyristor V4; the two AC input terminals of the rectifier bridge UR1 are connected to the first AC terminal and the second AC terminal respectively. terminal, the rectification output positive terminal is connected to the second anode of the bidirectional thyristor V3, the rectification output negative terminal is connected to the second anode of the bidirectional thyristor V4; the first anode of the bidirectional thyristor V1 is connected in parallel with the first anode of the bidirectional thyristor V3 and then connected to the second A controllable rectification output terminal; the second anode of the bidirectional thyristor V1 is connected to the first AC terminal; the first anode of the bidirectional thyristor V2 is connected in parallel with the first anode of the bidirectional thyristor V4 and then connected to the second controllable rectification output terminal; the bidirectional thyristor The second anode of V2 is connected to the second AC terminal.

The trigger control module is provided with an AC control input terminal and a rectification control input terminal; when the AC control signal input by the AC control input terminal is valid, the trigger control module controls the bidirectional thyristor V1 and the bidirectional thyristor V2 to trigger conduction when they cross zero; When the AC control signal input by the AC control input terminal is invalid, the trigger control module controls the triac V1 and the triac V2 to stop after zero crossing; when the rectification control signal input by the rectification control input terminal is valid, the trigger control module controls the triac V3 and the bidirectional thyristor V4 are triggered to conduct when they cross zero; when the rectification control signal input by the rectification control input terminal is invalid, the trigger control module controls the bidirectional thyristor V3 and the bidirectional thyristor V4 to stop after zero crossing.

The zero-crossing detection module is provided with a zero-crossing voltage input terminal and a zero-crossing pulse output terminal; the zero-crossing voltage input terminal is connected to the first AC terminal; the zero-crossing pulse output by the zero-crossing pulse output terminal is a positive pulse; the The zero-crossing pulse corresponds to the positive half-wave of the second AC power supply; the width of the zero-crossing pulse is smaller than the positive half-wave width of the second AC power supply; the positive half-wave of the second AC power supply is that the potential of the first AC terminal is higher than that of the second The second AC mains half-wave of the AC terminal potential.

The speed given module is provided with a speed given signal output terminal and a direction given signal output terminal.

The single-chip microcomputer control module includes a speed given signal input end, a direction given signal input end, a capture signal input end and two-way level signal output ends; the speed given signal input end is connected to the speed of the given speed module. given signal output terminal; the direction given signal input terminal is connected to the direction given signal output terminal of the speed given module; the capture signal input terminal is connected to the zero-crossing pulse output terminal of the zero-crossing detection module; the two The circuit level signal output terminals are respectively the AC control output terminal and the rectification control output terminal; the AC control output terminal and the rectification control output terminal are respectively connected to the AC control input terminal and the rectification control input terminal of the trigger control module.

The speed adjustment unit is composed of an adjustment power supply module, a waveform sampling module, a single-chip microcomputer adjustment module, and a motor drive module.

The regulated power supply module inputs a controllable rectified voltage and outputs a second DC working power supply, and is composed of a regulated power supply single-phase rectifier bridge and a second filtering and stabilizing circuit; the rectified negative terminal of the regulated power supply single-phase rectifier bridge is a reference ground . The second DC working power outputted by the regulating power supply module supplies power to the regulating module of the single-chip microcomputer.

The waveform sampling module is provided with a sampling waveform input terminal and a sampling pulse output terminal; the sampling waveform input terminal is connected to the second controllable rectification input terminal; the waveform sampling module makes the potential of the second controllable rectification input terminal higher than the first The potential waveform of a controllable rectification input terminal is detected and limited to obtain a sampling pulse; the positive pulse of the sampling pulse corresponds to the waveform whose potential of the second controllable rectification input terminal is higher than that of the first controllable rectification input terminal.

The single-chip microcomputer adjustment module has a capture input end, a speed adjustment output end, a direction control output end, and a brake control output end; the capture input end of the single-chip microcomputer adjustment module is connected to the sampling pulse output end of the waveform sampling module.

The motor drive module is used to drive a DC brushless motor, and is provided with a speed adjustment input end, a direction control input end, and a brake control input end; the speed adjustment input end is connected to the speed adjustment output end of the single-chip microcomputer adjustment module, and the direction control The input end is connected to the direction control output end of the single-chip microcomputer adjustment module, and the brake control input end is connected to the brake control output end of the single-chip microcomputer adjustment module.

The rectification control unit sends a speed control signal by controlling the controllable rectification voltage, and the speed control signal is composed of a pilot wave and a data wave.

The guide wave is composed of a rectification wave of y-1 power frequency period and an AC wave of 1 power frequency period, the rectification wave is in front and the AC wave is in the rear; y is an integer greater than or equal to 2.

The data wave is a controllable rectified voltage wave of x power frequency periods, and x is an integer greater than or equal to 2.

The speed control signal has a total of speed 1-n, and a total of n speed levels; the speed level of the speed given signal has speed 1-n; n is an integer greater than or equal to 2.

Among the controllable rectification voltage waves of x power frequency periods, 1 power frequency period corresponds to 1-bit data code; the controllable rectification voltage waves of x power frequency periods correspond to x-bit data codes.

The x-bit data code includes x-1-bit speed code and 1-bit direction code; the relationship between n and x is: n is less than or equal to 2 ^x-1 .

The data code, speed code and direction code are all binary codes.

The method that described single-chip microcomputer control module sends a speed control signal is,

Step 1, wait until the rising edge of the zero-crossing pulse is received and enter step 2;

Step 2, stop the AC output and start the rectification output;

Step 3, count the rising edge of the received zero-crossing pulse, and enter step 4 when the count value reaches y-1;

Step 4, stop the rectification output and start the AC output;

Step 5, wait until the rising edge of the zero-crossing pulse is received and enter step 6;

Step 6, sending out a controllable rectified voltage wave of one power frequency cycle;

Step 7, wait until the rising edge of the zero-crossing pulse is received and enter step 8;

Step 8, go to step 9 when the controllable rectified voltage wave of x power frequency periods has been issued, otherwise return to step 6;

Step 9, stop the rectification output and start the AC output.

The method of sending the speed control signal by the rectification control unit is:

Step A, read a given signal;

Step B, sending out a speed control signal;

Step C, judging whether the speed has changed, if the speed has changed, return to step B; if the speed has not changed, return to step C.

The method for the speed adjustment unit to receive the speed control signal and adjust the speed of the brushless DC motor is:

Step 1, motor control initialization, set the brushless DC motor to the braking state;

Step 2, judge whether there is a speed control signal; if there is no speed control signal, return to step 2; if there is a speed control signal, go to step 3;

Step 3, receiving a speed control signal;

Step 4, adjust the speed of the brushless DC motor; return to step 2.

The method of judging whether there is a speed control signal is judging whether there is a guide wave in the controllable rectified voltage. The method for judging whether there is a guide wave in the controllable rectification voltage is to judge the number of power frequency cycles in the low-level interval exceeding the power frequency cycle width after the power frequency cycle rectangular wave in the sampling pulse; if there is a power frequency cycle number in the sampling pulse If y-1 is a low-level interval, there is a pilot wave in the controllable rectification voltage; if there is no low-level interval with a power frequency period of y-1 in the sampling pulse, then there is no pilot wave in the controllable rectification voltage.

The method for judging the number of power frequency cycles in the low-level interval of the power frequency cycle width beyond the power frequency cycle width after the power frequency cycle rectangular wave in the sampling pulse is, for the low level pulses that exceed the power frequency cycle width after the power frequency cycle rectangular wave in the sampling pulse Measure the width, let the measured low-level pulse width exceeding the width of the power frequency cycle be W, then the number of power frequency cycles in the low-level interval is INT(W/20); the function of the INT function is to discard the decimal part and take all.

The method for receiving the speed control signal is to convert the controllable rectified voltage wave of x power frequency cycles into x-bit data code, convert the x-bit data code into speed code and direction code, and convert the speed code into speed control signal speed rating.

The controllable rectified voltage wave receiving x power frequency cycles is converted into x bit data codes, the method is: in the x power frequency cycle intervals after the pilot wave, when the sampling pulse of 1 power frequency cycle interval is low When the level is high, the corresponding data code of this bit is 1, and when the sampling pulse of a power frequency cycle interval is a rectangular wave with a duty ratio less than 50%, the corresponding data code of this bit is 0;

The method may be as follows: in the x power frequency period intervals after the guide wave, when the sampling pulse of 1 power frequency period interval is low level, the corresponding bit data code is 0, and when the sampling pulse of 1 power frequency period interval is When the sampling pulse is a rectangular wave whose duty ratio is less than 50%, the corresponding data code of this bit is 1.

The stop of the AC output refers to controlling the output of the AC control output terminal to output an invalid signal; the start of the rectification output refers to the control of the output of a valid signal at the rectification control output terminal; the start of the AC output refers to the control of the output of a valid signal at the AC control output terminal ; The said stopping the rectification output refers to controlling the rectification control output terminal to output an invalid signal.

The method for judging whether the speed changes is that the speed changes when the speed grade of the speed given signal changes or the direction given signal changes.

When the speed level of the speed control signal is level 1, the DC brushless motor is controlled to brake.

The beneficial effect of the present invention is that the speed of the DC brushless motor can be controlled remotely by using the power line, without the need for a remote controller or control line; the speed of the DC brushless motor can be divided into multiple levels according to needs; The value is the same as that of the AC wave, which will not cause instability of the power supply when the speed of the brushless DC motor is adjusted.

Description of drawings

Figure 1 is a block diagram of the system structure.

Figure 2 is a structural diagram of the rectification control unit.

Fig. 3 is a circuit diagram of an embodiment of a controllable rectification module.

Fig. 4 is a circuit diagram of an embodiment of a trigger control module.

Fig. 5 is a circuit diagram of an embodiment of the control part in the rectification control unit.

Fig. 6 is a schematic diagram of the waveform when the embodiment sends a speed control signal whose speed level is speed 15.

Fig. 7 is a speed control signal transmission method.

Fig. 8 is a structural diagram of the speed regulating unit.

Fig. 9 is a circuit diagram of an embodiment of the adjustment part of the speed adjustment unit.

Fig. 10 is a circuit diagram of Embodiment 1 of the motor drive module.

Fig. 11 is a circuit diagram of Embodiment 2 of the motor drive module.

Fig. 12 is the speed receiving and adjusting method.

detailed description

The present invention will be described in further detail below with reference to the accompanying drawings and examples, but the embodiments of the present invention are not limited thereto.

The structure block diagram of the device system for realizing the method of the present invention is shown in Fig. 1, which is composed of a rectification control unit and a speed adjustment unit. The rectification control unit receives single-phase 220V AC power from phase line input terminal L and neutral line input terminal N, and outputs controllable rectification voltage from the first controllable rectification output terminal AC1 and the second controllable rectification output terminal AC2. The speed adjustment unit inputs the controllable rectification voltage from the first controllable rectification input terminal AC1 and the second controllable rectification input terminal AC2 to control the speed of the brushless DC motor.

The structure of the rectification control unit is shown in Figure 2. It consists of a transformer, a control power supply module, a controllable rectification module, a zero-crossing detection module, a single-chip microcomputer control module, a trigger control module, and a speed given module.

The two input terminals of the transformer are the phase line input terminal L and the neutral line input terminal N, and the two output terminals are the first AC terminal L1 and the second AC terminal N1 respectively. The first AC terminal L1 and the second AC terminal N1 output the second AC power. The voltage effective value of the second AC power supply is lower than the voltage effective value of the single-phase 220V AC power supply input by the rectification control unit.

The embodiment of the controllable rectification module is shown in FIG. 3 , which consists of a rectifier bridge UR1 , a triac V1 , a triac V2 , a triac V3 , and a triac V4. The two AC input terminals of the rectifier bridge UR1 are respectively connected to the first AC terminal L1 and the second AC terminal N1, the rectification output positive terminal is connected to the second anode of the bidirectional thyristor V3, and the rectification output negative terminal is connected to the second anode of the bidirectional thyristor V4. Anode; the first anode of the bidirectional thyristor V1 is connected in parallel with the first anode of the bidirectional thyristor V3 and then connected to the first controllable rectification output terminal AC1; the second anode of the bidirectional thyristor V1 is connected to the first AC terminal L1; the second anode of the bidirectional thyristor V2 An anode is connected in parallel with the first anode of the bidirectional thyristor V4 and then connected to the second controllable rectification output terminal AC2; the second anode of the bidirectional thyristor V2 is connected to the second AC terminal N1.

The trigger pulse of the bidirectional thyristor V1 is input from its control pole K11 and the first anode K12, the trigger pulse of the bidirectional thyristor V2 is input from its control pole K21 and the first anode K22, and the trigger pulse of the bidirectional thyristor V3 is input from its control pole K31 and the first anode The anode K32 is input, and the trigger pulse of the bidirectional thyristor V4 is input from its control pole K41 and the first anode K42.

The rectifier bridge UR1 adopts a single-phase rectifier bridge pile, or uses 4 diodes to form a single-phase rectifier bridge instead.

The trigger control module is a circuit that satisfies the following functions: it is provided with an AC control input terminal and a rectification control input terminal; when the AC control signal input by the AC control input terminal is valid, the trigger control module controls the bidirectional thyristor V1 and the bidirectional thyristor V2 to trigger the triac when they cross zero. When the AC control signal input by the AC control input terminal is invalid, the trigger control module controls the triac V1 and the triac V2 to stop after zero crossing; when the rectification control signal input by the rectification control input terminal is valid, the trigger control module controls the triac V3 and V3 The bidirectional thyristor V4 is triggered to conduct when it crosses zero; when the rectification control signal input by the rectification control input terminal is invalid, the trigger control module controls the bidirectional thyristor V3 and the bidirectional thyristor V4 to stop after zero crossing.

The implementation of the trigger control module is shown in Figure 4. It consists of zero-cross trigger optocoupler U1-U4, input current-limiting resistor R1-R4, and output current-limiting resistor R5-R8. It is equipped with an AC control input terminal KJ and a rectification control input terminal. KZ. The interior of the zero-cross trigger optocoupler U1-U4 includes an input light-emitting diode, an output light-controlled bidirectional thyristor, and a zero-cross trigger circuit. The model of the zero-cross trigger optocoupler U1-U4 can be selected from MOC3041, MOC3042, MOC3043, MOC3061, MOC3062, and MOC3063.

The input current limiting resistor R1 is connected in series with the input light-emitting diode of the zero-crossing trigger optocoupler U1, and the series circuit is then connected in parallel to the first DC working power supply VDD1 and the AC control input terminal KJ. The input current limiting resistor R1 is connected in series with the anode of the input light-emitting diode of the zero-crossing trigger optocoupler U1, as shown in Figure 4; the input current-limiting resistor R1 can also be connected in series with the cathode of the input light-emitting diode of the zero-crossing trigger optocoupler U1.

The input current limiting resistor R2 is connected in series with the input LED of the zero-crossing trigger optocoupler U2, and the series circuit is connected in parallel to the first DC working power supply VDD1 and the AC control input terminal KJ. The input current limiting resistor R3 is connected in series with the input LED of the zero-crossing trigger optocoupler U3, and the series circuit is then connected in parallel to the first DC working power supply VDD1 and the rectification control input terminal KZ. The input current limiting resistor R4 is connected in series with the input light-emitting diode of the zero-crossing trigger optocoupler U4, and the series circuit is then connected in parallel to the first DC working power supply VDD1 and the rectification control input terminal KZ. The input current-limiting resistors R2-R4 can be connected in series with the anode of the input light-emitting diode of the corresponding zero-crossing trigger optocoupler, as shown in Figure 4; they can also be connected in series with the cathode of the input light-emitting diode of the corresponding zero-crossing trigger optocoupler.

The output current-limiting resistor R5 is connected in series with the internal output photo-controlled bidirectional thyristor of the zero-crossing trigger optocoupler U1, and then connected in parallel to the control pole K11 and the first anode K12 of the bidirectional thyristor V1; the output current-limiting resistor R6 is connected to the internal output of the zero-crossing trigger optocoupler U2 The light-controlled bidirectional thyristor is connected in series and then connected in parallel to the control pole K21 and the first anode K22 of the bidirectional thyristor V2; the output current limiting resistor R7 is connected in series with the internal output of the zero-crossing trigger optocoupler U3 and then connected in parallel to the control of the bidirectional thyristor V3 The pole K31 and the first anode K32; the output current limiting resistor R8 is connected in series with the internal output photo-controlled bidirectional thyristor of the zero-crossing trigger optocoupler U4 and then connected in parallel to the control pole K41 and the first anode K42 of the bidirectional thyristor V4.

The control part of the rectification control unit includes a control power supply module, a zero-crossing detection module, a single-chip microcomputer control module, and a speed setting module, and its embodiment circuit is shown in FIG. 5 .

The input of the control power supply module is the second AC power supply, and the output is the first DC working power supply VDD1 provided to the rectification control unit. In the embodiment shown in Fig. 5, the control power supply module is composed of diode D01, diode D02, diode D03, diode D04, capacitor C1, and three-terminal regulator U5. Diode D01, diode D02, diode D03, and diode D04 form a control power supply single-phase rectifier bridge; capacitor C1 is connected in parallel to the DC voltage output end of the control power supply single-phase rectifier bridge, and acts as a filter; the input terminal VIN of the three-terminal regulator U5 is connected to The rectified positive terminal of the single-phase rectifier bridge of the control power supply; the first DC working power supply VDD1 is output from the output terminal VOUT of the three-terminal regulator U5. The rectification negative terminal of the single-phase rectification bridge of the control power supply is the common ground. The three-terminal regulator U5 chooses H7133.

The control power supply module can also adopt other implementation schemes. The control power supply single-phase rectifier bridge composed of diode D01, diode D02, diode D03 and diode D04 can be replaced by a single-phase rectifier bridge stack, and the three-terminal voltage regulator U5 can use a voltage regulator circuit or a DC/DC voltage regulator.

The zero-crossing detection module is a circuit with the following functions: a zero-crossing voltage input terminal and a zero-crossing pulse output terminal are provided; the zero-crossing voltage input terminal is connected to the first AC terminal; the zero-crossing pulse output by the zero-crossing pulse output terminal is a positive pulse; The zero-crossing pulse corresponds to the positive half-wave of the second AC power supply; the width of the zero-crossing pulse is smaller than the width of the positive half-wave of the second AC power supply; the positive half-wave of the second AC power supply is the first AC terminal potential higher than the second AC terminal potential Two half-wave AC power.

In the embodiment of FIG. 5, the zero-crossing detection module is a wave detection and shaping circuit, which is composed of a diode D1, a resistor R9, and a voltage regulator tube DW1. Both ends of the resistor R9 are respectively connected to the cathode of the diode D1 and the cathode of the voltage regulator DW1 , the anode of the diode D1 is connected to the first AC terminal L1 , and the anode of the voltage regulator DW1 is connected to the common ground. The cathode of the Zener tube DW1 is the zero-crossing pulse output terminal for outputting the zero-crossing pulse.

The speed given module is provided with a speed given signal output terminal and a given direction signal output terminal, the speed given signal output terminal outputs a given speed signal, and the given direction signal output terminal outputs a given direction signal. In the embodiment shown in FIG. 5 , the speed setting module uses the potentiometer RW1 to divide the voltage of the first DC working power supply VDD1 , and the obtained speed setting signal is the speed setting voltage. Divide the given speed voltage output by the potentiometer RW1 into n intervals on average, the speed grade of the speed given signal in the lowest voltage interval is speed 1, and the speed grade of the speed given signal in the highest voltage interval is speed n; the n of the speed given voltage The intervals correspond to the speed 1-n of the speed grade; n is an integer greater than or equal to 2. The speed given module can also be realized by other devices such as rotary encoder, dial switch, pulse potentiometer, etc. In the embodiment of Fig. 5, the speed given module uses the direction switch SWD to output the given direction signal, one end of the direction switch SWD is connected to the common ground, and the other end is the output end of the given direction signal.

The single-chip microcomputer control module includes 1 speed given signal input terminal, 1 direction given signal input terminal, 1 captured signal input terminal, and 2 level signal output terminals. 1 speed reference signal input terminal is connected to the speed reference signal output terminal of the speed reference module; 1 direction reference signal input terminal is connected to the direction reference signal output terminal of the speed reference module; 1 capture signal input terminal Connect to the zero-crossing pulse output terminal of the zero-crossing detection module and input the zero-crossing pulse; the two level signal output terminals are the AC control output terminal KJ and the rectification control output terminal KZ, respectively connected to the AC control input terminal KJ of the trigger control module , Rectification control input terminal KZ.

In the embodiment of Fig. 5, the single-chip microcomputer control module is composed of a single-chip microcomputer MCU1 and a crystal oscillator XT1, and the model of the single-chip microcomputer MCU1 is MSP430G2553. The analog voltage input terminal A0 (P1.0) of the single-chip microcomputer MCU1 is the input terminal of the speed given signal, and the output voltage of the potentiometer RW1 is connected to the analog voltage input terminal A0 (P1.0) of the single-chip microcomputer MCU1. If other devices are used to send the speed given signal in the form of switch value and digital value, it can be input from the I/O port of the single-chip microcomputer MCU1. The single-chip microcomputer MCU1 performs A/D conversion on the speed reference voltage input by the analog voltage input terminal A0, or reads the input signal of the I/O port to obtain the speed grade of the speed reference signal. P2.0 of the single-chip microcomputer MCU1 is the capture signal input terminal, which is connected to the zero-crossing pulse output terminal of the zero-crossing detection module. P1.3 of the single-chip microcomputer MCU1 is the input terminal of the direction given signal, which is connected to the output terminal of the given direction signal of the speed given module. P1.1 and P1.2 of the MCU1 are level signal output terminals, among which P1.1 is the AC control output terminal KJ, and P1.2 is the rectification control output terminal KZ; the AC control output terminal KJ and the rectification control output terminal KZ are respectively Connect to the AC control input terminal KJ and the rectification control input terminal KZ of the trigger control module.

The first controllable rectification output terminal AC1 and the second controllable rectification output terminal AC2 of the rectification control unit output the controllable rectification voltage, and the rectification control unit sends the speed control signal by controlling the controllable rectification voltage, and the speed control signal is composed of the guide wave and the data wave composition. The effective value of the controllable rectified voltage is the same as the effective value of the voltage of the second AC power supply.

The speed control signal has a total of speeds 1-n, and a total of n speed levels.

The guide wave is composed of y-1 rectified waves of power frequency cycle and 1 AC wave of power frequency cycle, the rectified wave is in front and the AC wave is behind; y is an integer greater than or equal to 2.

The data wave is a controllable rectified voltage wave of x power frequency periods, and x is an integer greater than or equal to 2. The speed control signal has a total of speed 1-n, and a total of n speed grades; the speed 1-n of the speed grade of the speed control signal corresponds to the speed 1-n of the speed reference signal speed grade. The state of the brushless DC motor corresponding to speed 1 of the speed level is the braking state.

Among the controllable rectification voltage waves of x power frequency cycles, 1 power frequency cycle corresponds to 1-bit data code, and the controllable rectification voltage wave of x power frequency cycles corresponds to x-bit data codes; in each power frequency cycle, it can When the controllable rectification voltage wave is an AC wave, the corresponding 1-bit data code is 0; in each power frequency cycle, when the controllable rectification voltage wave is a rectification wave, the corresponding 1-bit data code is 1. Or in the controllable rectification voltage wave of x power frequency cycles, 1 power frequency cycle corresponds to 1-bit data code; in each power frequency cycle, when the controllable rectification voltage wave is an AC wave, the corresponding 1-bit data code is 1; in each power frequency cycle, when the controllable rectification voltage wave is a rectification wave, the corresponding 1-bit data code is 0.

The x-bit data code includes x-1-bit speed code and 1-bit direction code. At this time, the relationship between n and x is: n is less than or equal to 2 ^x-1 . When composing the data code, the x-1 bit speed code is in front, and the 1 bit direction code is behind. The speed code is determined by the speed given signal, and the direction code is determined by the direction given signal.

The data code, speed code and direction code are all binary codes.

The embodiment of the waveform when the rectification control unit sends the speed control signal is shown in Figure 6. In the embodiment shown in Fig. 6, y is equal to 3, x is equal to 6, and the speed control signal has a total speed of 1-32, a total of 32 speed levels.

Figure 6 sends the speed control signal whose speed level is speed 15. Figure 6(a) shows the waveform of the controllable rectification voltage, in which the T1 interval is the guide wave, which consists of two power frequency cycles of rectification waves and one power frequency cycle of AC waves. The T2 interval is a data wave, that is, a controllable rectified voltage wave of 6 power frequency cycles. Among the controllable rectification voltage waves of 6 power frequency cycles in the embodiment, 1 power frequency cycle corresponds to 1 bit of data code; in each power frequency cycle, when the controllable rectification voltage wave is an AC wave, the corresponding data code is 0; in each power frequency cycle, when the controllable rectification voltage wave is a rectification wave, the corresponding data code is 1; the 6 power frequency cycles are AC wave, rectification wave, rectification wave, rectification wave, AC wave, AC Wave, the corresponding 6-digit data code is 011100. The first 5 digits of the 6-digit data code is the speed code, the range of the speed code is 00000-11111, and the range of the representative speed level is speed 1-32. In the data wave of the embodiment shown in Figure 6, the corresponding 5-bit data code is 01110, and the speed grade of the speed control signal is speed 15. The last 1 bit of the 6-bit data code is a direction code, and the direction code corresponds to the T3 interval. In the example, it is an AC wave with one power frequency cycle, and the direction code is 0.

x-1-bit speed code and 1-bit direction code form the data code. It is also possible to use the method of 1-bit direction code in front and x-1-bit speed code in the back. At this time, the controllable rectified voltage shown in Figure 6 is still sent Waveform, the first bit of the 6-bit data code is the direction code, and the direction code is 0; the 5-bit data code is 11100, representing the speed level of the speed control signal as speed 29.

When the brushless DC motor does not need to control the direction, the x-bit data code constitutes the x-bit speed code, and there is no direction code in the data code. At this time, the relationship between n and x is: n is less than or equal to 2 ^x .

The steps of sending a speed control signal by the single-chip microcomputer control module are as follows:

Step 1, wait until the rising edge of the zero-crossing pulse is received and enter step 2;

Step 2, stop the AC output and start the rectification output;

Step 3, count the rising edge of the received zero-crossing pulse, and enter step 4 when the count value reaches y-1;

Step 4, stop the rectification output and start the AC output;

Step 5, wait until the rising edge of the zero-crossing pulse is received and enter step 6;

Step 6, sending out a controllable rectified voltage wave of one power frequency cycle;

Step 7, wait until the rising edge of the zero-crossing pulse is received and enter step 8;

Step 8, go to step 9 when the controllable rectified voltage wave of x power frequency periods has been issued, otherwise return to step 6;

Step 9, stop the rectification output and start the AC output.

When the rectifier control unit maintains the normal state of not sending out speed control signals, the single-chip control module controls the AC control output terminal KJ to output a valid signal, and the rectifier control output terminal KZ outputs an invalid signal, and the zero-crossing triggers the input light-emitting diodes of the optocouplers U1 and U2 to conduct On, the zero-crossing triggers the input light-emitting diodes of optocoupler U3 and U4 to cut off, the triac V1 and triac V2 are turned on, the triac V3 and triac V4 are cut off, the first controllable rectification output terminal AC1, the second controllable rectification output terminal The controllable rectified voltage output by terminal AC2 is AC voltage. In the embodiment shown in FIG. 4 , the signals of the AC control output terminal KJ and the rectification control output terminal KZ output by the single-chip microcomputer control module are low-level active.

The zero-crossing pulse output by the zero-crossing detection module shown in FIG. 5 corresponds to the positive half-wave of the second AC power supply, and the width of the zero-crossing pulse is smaller than the width of the positive half-wave of the second AC power supply. The positive half-wave of the second AC power source is the second AC power half-wave in which the potential of the first AC terminal is higher than the potential of the second AC terminal.

After the single-chip microcomputer control module detects the rising edge of the zero-crossing pulse corresponding to half-wave 1 in Figure 6, enter step 2. Said stopping the AC output refers to controlling the AC control output terminal KJ to output an invalid signal, and starting from the next zero-crossing point of the second AC power supply, the bidirectional thyristor V1 and the bidirectional thyristor V2 are cut off; said starting rectification output refers to controlling the rectification control The output terminal KZ outputs a valid signal. From the next zero-crossing point of the second AC power supply, the bidirectional thyristor V3 and the bidirectional thyristor V4 are turned on, and the controllable output of the first controllable rectification output terminal AC1 and the second controllable rectification output terminal AC2 The rectified voltage is a rectified voltage.

The said stop rectification output means to control the rectification control output terminal KZ to output an invalid signal, starting from the next zero-crossing point of the second AC power supply, the bidirectional thyristor V3 and the bidirectional thyristor V4 are cut off; the said start of the AC output means to control the AC control The output terminal KJ outputs a valid signal. Starting from the next zero-crossing point of the second AC power supply, the bidirectional thyristor V1 and the bidirectional thyristor V2 are turned on, and the controllable output of the first controllable rectification output terminal AC1 and the second controllable rectification output terminal AC2 The rectified voltage is AC voltage.

The method for sending the controllable rectified voltage wave of one power frequency cycle is to judge whether the controllable rectified voltage wave of the power frequency cycle to be sent is an AC wave or a rectified wave, and if it is an AC wave, stop the rectification output, Start the AC output; if it is a rectified wave, stop the AC output and start the rectified output.

Each single power frequency cycle in the controllable rectified voltage wave is an AC wave or a rectified wave; the AC wave of a single power frequency cycle consists of a positive half wave of a single-phase AC power supply and a negative half wave of a single-phase AC power supply The positive half wave is in the front, and the negative half wave is in the back; the rectification wave of the single power frequency cycle is composed of two rectification half waves, the first rectification half wave corresponds to the second AC power positive half wave, and the second rectification wave The half-wave corresponds to the negative half-wave of the second AC power supply. The time of the power frequency cycle is 20ms. The single power frequency cycle is 1 power frequency cycle.

The method for sending the speed control signal by the rectification control unit is shown in Figure 7, including:

Step A, read a given signal;

Step B, sending out a speed control signal;

Step C, judging whether the speed has changed, if the speed has changed, return to step B; if the speed has not changed, return to step C.

The method of judging whether the speed changes is that the speed level of the speed given signal changes, or the direction given signal changes, and the speed changes.

The structure of the speed adjustment unit is shown in Figure 8, which consists of an adjustment power supply module, a waveform sampling module, a single-chip microcomputer adjustment module, and a motor drive module.

The adjustment part of the speed adjustment unit includes an adjustment power supply module, a waveform sampling module, and a single-chip microcomputer adjustment module, the embodiment of which is shown in FIG. 9 .

The regulating power supply module provides the second DC working power supply VDD2 for the speed regulating unit. In the embodiment of FIG. 9 , the regulating power supply module is composed of a diode D05 , a diode D06 , a diode D07 , a diode D08 , a capacitor C2 and a three-terminal regulator U6. Diode D05, diode D06, diode D07, and diode D08 form a single-phase rectifier bridge for regulating power supply; capacitor C2 is connected in parallel to the DC voltage output end of the single-phase rectifier bridge for regulating power supply, and acts as a filter; the input terminal VIN of the three-terminal regulator U6 is connected to Regulate the rectified positive terminal of the single-phase rectifier bridge of the power supply; the second DC working power supply VDD2 is output from the output terminal VOUT of the three-terminal regulator U6. The rectification negative terminal of the single-phase rectification bridge of the regulating power supply is the reference ground. The three-terminal regulator U6 chooses H7133.

The regulating power supply module can also adopt other implementation schemes. The adjustable power single-phase rectifier bridge composed of diode D05, diode D06, diode D07, and diode D08 can be replaced by a single-phase rectifier bridge stack, and the three-terminal voltage regulator U6 can use a voltage regulator circuit or a DC/DC voltage regulator.

The waveform sampling module is a circuit with the following functions: a sampling waveform input terminal and a sampling pulse output terminal are provided; the sampling waveform input terminal is connected to the second controllable rectification input terminal; the waveform sampling module sets the potential of the second controllable rectification input terminal higher than The waveform of the potential of the first controllable rectification input terminal is detected and limited to obtain a sampling pulse; the positive pulse of the sampling pulse corresponds to the waveform whose potential of the second controllable rectification input terminal is higher than that of the first controllable rectification input terminal.

In the embodiment of FIG. 9, the waveform sampling module is a wave detection and shaping circuit, which is composed of a diode D2, a resistor R12, and a voltage regulator tube DW2. The two ends of the resistor R12 are respectively connected to the cathode of the diode D2 and the cathode of the voltage regulator DW2; the anode of the diode D2 is the sampling waveform input terminal, which is connected to the second controllable rectification input terminal AC2; the anode of the voltage regulator DW2 is connected to the reference ground; The cathode of tube DW2 is the sampling pulse output terminal.

The single-chip microcomputer adjustment module has a capture input terminal, a speed adjustment output terminal ADJ, a direction control output terminal DIR, and a brake control output terminal BRAK, and the capture input terminal is connected to the sampling pulse output terminal of the waveform sampling module. The output type of the direction control output terminal DIR and the brake control output terminal BRAK is switch value; the output type of the speed adjustment output terminal ADJ is PWM pulse or analog voltage.

In the embodiment of Fig. 9, the single-chip microcomputer adjustment module is composed of single-chip microcomputer MCU2 and crystal oscillator XT2. PWM pulse; direction control output DIR is P1.4, brake control output BRAK is P1.5, P1.4, P1.5 output level control signal.

The motor drive module is used to drive the DC brushless motor, and the DC brushless motor driver and the DC brushless motor drive chip provided with a PWM pulse speed regulation input terminal or an analog voltage speed regulation input terminal are applicable to the present invention. FIG. 10 shows the circuit of Embodiment 1 using a DC brushless motor drive chip, and FIG. 11 shows the circuit of Embodiment 2 using a DC brushless motor driver.

In the embodiment shown in Figure 10, the motor drive module consists of a motor drive chip F310, a three-phase full-bridge MOSFET drive chip U7, diodes D31-D34, capacitors C31-C32, resistors R31-R48, triode V31, potentiometer RW31, thermistor Resistor NTC composition.

In the embodiment shown in Fig. 10, diodes D31-D34 form a single-phase bridge rectifier circuit to rectify the controllable rectification voltage input from the first controllable rectification input terminal AC1 and the second controllable rectification input terminal AC2, and then filter through the capacitor C31 Get the motor drive power U+, and supply power to the motor drive chip F310 and the three-phase full-bridge MOSFET drive chip U7. The negative terminal of the single-phase bridge rectifier circuit is connected to the reference ground.

In the embodiment of Fig. 10, resistor R31, resistor R32, triode V31, and capacitor C32 form a PWM pulse/analog voltage conversion circuit, which converts the PWM pulse of the speed adjustment input ADJ into an analog voltage speed adjustment signal, and the analog voltage speed adjustment signal is connected to The speed regulation voltage input terminal SREF of the motor drive chip F310. The DC power VDD6 is provided by the +6V power output terminal of the motor drive chip F310. If the output type of the speed adjustment output terminal ADJ of the single chip microcomputer adjustment module is an analog voltage, then the speed adjustment voltage input terminal SREF of the motor drive chip F310 is directly connected to the speed adjustment output terminal ADJ, without a PWM pulse/analog voltage conversion circuit.

In the embodiment of FIG. 10, the drive input terminals HU, LU, HV, LV, HW, and LW of the three-phase full-bridge MOSFET drive chip U7 are respectively connected to the drive output terminals PWM_HU, PWM_LU, PWM_HV, PWM_LV, PWM_HW, PWM_LW; the three-phase output terminals U, V, and W of the three-phase full-bridge MOSFET driver chip U7 are connected to the three-phase input terminal of the brushless DC motor M31; the negative power supply input terminal V of the three-phase full-bridge MOSFET driver chip U7 is connected to the resistor R39 is connected to reference ground. The sampling voltage on the resistor R39 is connected to the sampling current input terminal ITRIP of the motor drive chip F310; the current-limiting threshold voltage ILIMIT is determined by the potentiometer RW31.

In the embodiment of Fig. 10, the RPI voltage is determined by the resistor R33 and the resistor R34, and the RPI voltage determines the size of the motor starting current; the RSF voltage is determined by the resistor R35 and the resistor R36, and the RSF voltage determines the commutation frequency when the motor starts; RSD The voltage is determined by resistors R37 and R38, and the automatic restart time after overcurrent is set by RSD.

In the embodiment shown in FIG. 10 , VLIMIT is the reference threshold voltage for overheating protection, determined by resistors R41 and R42; VTH is the input decision voltage, determined by resistor R40 and thermistor NTC.

In the embodiment shown in Fig. 10, the resistors R43-R48 form a voltage divider circuit to collect the feedback voltage of the phase terminals to detect the counter electromotive force, and the three-phase feedback voltages are respectively connected to the feedback input terminals EMF_U, EMF_V, and EMF_W of the motor driver chip F310.

In the embodiment of FIG. 10 , the direction control output terminal DIR and the brake control output terminal BRAK of the single-chip adjustment module are respectively connected to the direction control input terminal F/R and the brake input terminal RESET of the motor drive chip F310. The brake input terminal RESET of the motor drive chip F310 is also called the reset control terminal RESET.

In the embodiment of FIG. 10 , the power supply terminal VCC of the motor driving chip F310 is connected to the motor driving power supply U+, and the ground terminal GND is connected to the reference ground.

In the embodiment of FIG. 10 , the DC brushless motor M31 is a DC brushless motor without a Hall sensor.

In the embodiment shown in FIG. 11 , the motor drive module is composed of a brushless motor driver U61, diodes D61-D64, capacitors C61-C62, resistors R61-R62, and a transistor V61. The model of brushless motor driver U61 is BLD-70.

In the embodiment shown in Fig. 11, diodes D61-D64 form a single-phase bridge rectification circuit to rectify the controllable rectification voltage input from the first controllable rectification input terminal AC1 and the second controllable rectification input terminal AC2, and then filter through the capacitor C61 Get the motor driving power supply V+, and supply power to the brushless motor driver U61. The negative terminal of the single-phase bridge rectifier circuit is connected to the reference ground.

In the embodiment of Fig. 11, resistor R61, resistor R62, transistor V61, and capacitor C62 form a PWM pulse/analog voltage conversion circuit, which converts the PWM pulse of the speed adjustment input ADJ into an analog voltage speed adjustment signal, and the analog voltage speed adjustment signal is connected to The speed regulation voltage input terminal SV of the brushless motor driver U61. The DC power VDD62 is provided by the power output terminal VCC (+6.25V) of the brushless motor driver U61.

In the embodiment of Fig. 11, the three-phase phase line terminals U, V, W of the brushless DC motor M61 are connected to the three-phase output terminals U, V, W of the brushless motor driver U61; the Hall signal output of the brushless DC motor M61 The terminals HU, HV, and HW are connected to the Hall signal input terminals HU, HV, and HW of the brushless motor driver U61; the Hall power supply of the brushless DC motor M61 is supplied by the power output terminal VCC (+6.25V) of the brushless motor driver U61 Provided, H+ is connected to the power output terminal VCC of the brushless motor driver U61, and H- is connected to the reference ground.

In the embodiment of FIG. 11 , the direction control output terminal DIR and the brake control output terminal BRAK of the single-chip adjustment module are respectively connected to the direction control input terminal F/R and the brake input terminal BRK of the brushless motor driver U61.

In the embodiment of FIG. 11 , the positive power terminal DC+ of the brushless motor driver U61 is connected to the motor driving power V+, and the negative power terminal DC− is connected to the reference ground.

The speed adjustment unit receives the speed control signal and adjusts the speed of the brushless DC motor. The method is shown in Figure 12, including:

Step 1, motor control initialization, set the brushless DC motor to the braking state;

Step 2, judge whether there is a speed control signal; if there is no speed control signal, return to step 2; if there is a speed control signal, go to step 3;

Step 3, receiving a speed control signal;

Step 4, adjust the speed of the brushless DC motor; return to step 2.

When switching between forward and reverse rotation, it is necessary to first output a braking signal through the brake control output terminal BRAK to brake the motor. After the braking is completed, output a direction control signal from the direction control output terminal DIR to realize the reverse rotation of the motor. Direct switching without braking to achieve forward and reverse may cause a sharp increase in load current and damage the drive circuit.

The method of adjusting the speed of the brushless DC motor is to control the speed of the brushless DC motor according to the speed level corresponding to the speed code when the direction code does not change in the speed control signal received by the single-chip adjustment module; the speed control signal received by the single-chip adjustment module In the signal, when the direction code changes, first control the braking of the brushless DC motor, and then control the speed of the brushless DC motor according to the speed level corresponding to the speed code.

In the method for adjusting the speed of the DC brushless motor, when the speed level corresponding to the speed control signal received by the single-chip microcomputer adjustment module is level 1, the DC brushless motor is controlled to brake.

To determine whether there is a speed control signal, the method is to determine whether there is a guide wave in the controllable rectification voltage input from the first controllable rectification input terminal AC1 and the second controllable rectification input terminal AC2.

The speed control signal is received by receiving controllable rectification voltage waves of x power frequency periods and converting the controllable rectification voltage waves of x power frequency periods into x-bit data codes.

The function of the waveform sampling module is to detect and shape the controllable rectified voltage. In the embodiment of Fig. 9, the waveform sampling module detects and limits the waveform whose potential of the first controllable rectification input terminal AC1 is lower than that of the second controllable rectification input terminal AC2 to obtain a sampling pulse, and outputs it to the capture input terminal of the single-chip microcomputer adjustment module; The positive pulse of the sampling pulse corresponds to the half-wave in which the potential of the first controllable rectification input terminal is lower than the potential of the second controllable rectification input terminal, and the positive pulse width of the sampling pulse is smaller than the half-wave width. An example of the sampling pulse whose speed level is speed 15 in the speed control signal is shown in Figure 6(b); when the controllable rectified voltage is an AC voltage, the sampling pulse is a pulse with a duty cycle less than 50% and the same frequency as the second AC power supply Rectangular wave; when the controllable rectified voltage is a rectified voltage, the sampling pulse is at low level.

In the embodiment shown in FIG. 6 , the guiding wave is composed of a rectified wave of 2 power frequency periods and an AC wave of 1 power frequency period, and the sampling pulse before the guiding wave is a rectangular wave whose period is the power frequency period. The rectified wave of 2 power frequency cycles should make the sampling pulse appear at a low level with a width of 40ms, that is, the interval of 2 power frequency cycles, but in fact, the guiding wave makes the sampling pulse appear with a width close to 50ms, that is, 2.5 power frequencies The low level in the cycle interval is the low level interval T4 shown in Figure 6; the low level in the extra 0.5 power frequency cycle interval is generated by the positive half wave of the AC wave in the following 1 power frequency cycle The negative half-wave of the AC wave of 1 power frequency cycle of the guide wave causes a high level with a width of 0.5 power frequency cycle interval to appear in the sampling pulse, such as the high level interval T5 shown in Figure 6 .

To judge whether the controllable rectification voltage has a guide wave, the method is to judge the number of power frequency cycles in the low-level interval exceeding the power frequency cycle width after the power frequency cycle rectangular wave in the sampling pulse; if there is a power frequency cycle number in the sampling pulse, it is y- In the low-level interval of 1, there is a pilot wave in the controllable rectification voltage; if there is no low-level interval with a power frequency period of y-1 in the sampling pulse, there is no pilot wave in the controllable rectification voltage.

The method of judging the number of power frequency cycles in the low-level interval exceeding the width of the power frequency cycle after the power frequency cycle rectangular wave in the sampling pulse is to measure the width of the low level pulse exceeding the power frequency cycle width after the power frequency cycle rectangular wave in the sampling pulse , assuming that the measured low-level pulse width exceeding the width of the power frequency cycle is W, then the number of power frequency cycles in the low-level interval is INT(W/20); the function of the INT function is to round off the decimal part.

Among the controllable rectified voltage waves of x power frequency cycles of the data wave, one power frequency cycle corresponds to one bit of data code, and the voltage wave of each power frequency cycle can be an AC wave or a rectified wave. When the voltage wave of one power frequency cycle is a rectified wave, the corresponding sampling pulse is a low level in the interval of one power frequency cycle; when the voltage wave of one power frequency cycle is an AC wave, the corresponding sampling pulse It is a rectangular wave whose duty cycle is less than 50%. In the embodiment shown in Figure 6, the data wave is a controllable rectified voltage wave of six consecutive power frequency cycles, that is, the AC wave corresponding to the interval T6, the rectified wave corresponding to the interval T7, the rectified wave corresponding to the interval T8, and the rectified wave corresponding to the interval T9. The rectified wave, the AC wave corresponding to interval T10 and the AC wave corresponding to interval T11; the 5-bit speed code is 01110, and the 1-bit direction code is 0. The speed rating is speed 15.

The method of converting the controllable rectified voltage wave of x power frequency periods into x-bit data codes is that in the x power frequency period intervals after the pilot wave, when the sampling pulse of 1 power frequency period interval is low level, The corresponding data code of this bit is 1, and when the sampling pulse of one power frequency cycle interval is a rectangular wave with a duty ratio less than 50%, the corresponding data code of this bit is 0. Or, in the x power frequency period interval after the guide wave, when the sampling pulse of 1 power frequency period interval is low level, the corresponding bit data code is 0, when the sampling pulse of 1 power frequency period interval When it is a rectangular wave whose duty cycle is less than 50%, the corresponding data code of this bit is 1.

Speed codes can be converted into speed grades by methods such as calculation and table lookup. In the embodiment, the range of the 5-digit speed code is 00000-11111, representing the range of speed grades from speed 1-32; when the speed code is 00000, the speed grade is speed 1; when the speed code is 00001, the speed grade is speed 2; When the speed code is 00010, the speed grade is speed 3; by analogy, when the speed code is 11111, the speed grade is speed 32.

When the DC brushless motor does not need to control the direction, the speed given module does not need the direction given signal output terminal, the single-chip microcomputer control module does not need the direction given signal input terminal, the single-chip microcomputer adjustment module does not need the direction control output terminal, and the motor drive module does not need the direction control input terminal .

The controllable rectification voltage directly supplies power to the adjustment power supply module, motor drive module and waveform sampling module of the speed adjustment unit. Provide power; when the controllable rectification voltage is zero, the power supply current of the adjustable power supply module and the motor drive module is also zero; the waveform sampling module is a non-linear resistive load, and when the controllable rectification voltage is zero, the power supply current of the waveform sampling module is zero. Therefore, when the controllable rectification voltage is zero, the power supply current it provides to the speed regulating unit is zero. Therefore, when the rectification control unit stops the AC output, starts the rectification output, or stops the rectification output and starts the switching of the AC output at the zero crossing point of the second AC power supply, the triac V1, the triac V2 and the triac V3, V4 The current can be successfully commutated without causing a short circuit of the power supply.

The present invention has following characteristics:

①Use the power line to control the speed of the brushless DC motor from a long distance, without remote control or control line;

②The speed of brushless DC motor can be divided into multiple levels according to the needs;

③The rectified wave is used to transmit the speed control signal, and its effective value is the same as that of the AC wave, which will not cause the instability of the power supply when the speed of the brushless DC motor is adjusted.

Claims (10)

1. A method for long-distance speed regulation of a brushless DC motor, characterized in that: It is realized by a device composed of a rectification control unit and a speed regulation unit; The rectification control unit is provided with a phase line input terminal, a neutral line input terminal, a first controllable rectification output terminal, and a second controllable rectification output terminal; the phase line input terminal and the neutral line input terminal are input to a single-phase 220V AC power supply ; The first controllable rectification output terminal and the second controllable rectification output terminal output a controllable rectification voltage; The speed adjustment unit is provided with a first controllable rectification input terminal and a second controllable rectification input terminal, and the first controllable rectification input terminal and the second controllable rectification input terminal are respectively connected to the first controllable rectification input terminal of the rectification control unit. Controlled rectification output terminal, second controllable rectification output terminal; The rectification control unit is composed of a transformer, a control power supply module, a controllable rectification module, a zero-crossing detection module, a single-chip microcomputer control module, a trigger control module, and a given speed module; The two input terminals of the transformer are the phase line input terminal and the neutral line input terminal respectively, and the two output terminals are respectively the first AC terminal and the second AC terminal; the first AC terminal and the second AC terminal output the second AC power; The control power supply module is composed of a control power supply single-phase rectifier bridge and a first filtering and stabilizing circuit, and outputs a first DC working power supply; the two AC input ends of the control power supply single-phase rectifier bridge are respectively connected to the first AC terminal , the second AC terminal; The rectified negative terminal of the single-phase rectifier bridge of the control power supply is a common ground; the first DC working power outputted by the control power supply module supplies power to the single-chip microcomputer control module; The controllable rectification module is composed of a rectifier bridge UR1, a bidirectional thyristor V1, a bidirectional thyristor V2, a bidirectional thyristor V3, and a bidirectional thyristor V4; the two AC input terminals of the rectifier bridge UR1 are connected to the first AC terminal and the second AC terminal respectively. terminal, the rectification output positive terminal is connected to the second anode of the bidirectional thyristor V3, the rectification output negative terminal is connected to the second anode of the bidirectional thyristor V4; the first anode of the bidirectional thyristor V1 is connected in parallel with the first anode of the bidirectional thyristor V3 and then connected to the second A controllable rectification output terminal; the second anode of the bidirectional thyristor V1 is connected to the first AC terminal; the first anode of the bidirectional thyristor V2 is connected in parallel with the first anode of the bidirectional thyristor V4 and then connected to the second controllable rectification output terminal; the bidirectional thyristor The second anode of V2 is connected to the second AC terminal; The trigger control module is provided with an AC control input terminal and a rectification control input terminal; when the AC control signal input by the AC control input terminal is valid, the trigger control module controls the bidirectional thyristor V1 and the bidirectional thyristor V2 to trigger conduction when they cross zero; When the AC control signal input by the AC control input terminal is invalid, the trigger control module controls the triac V1 and the triac V2 to stop after zero crossing; when the rectification control signal input by the rectification control input terminal is valid, the trigger control module controls the triac V3 trigger conduction when the triac V4 and the triac V4 cross zero; when the rectification control signal input by the rectification control input terminal is invalid, the trigger control module controls the bidirectional thyristor V3 and the bidirectional thyristor V4 to stop after zero crossing; The zero-crossing detection module is provided with a zero-crossing voltage input terminal and a zero-crossing pulse output terminal; the zero-crossing voltage input terminal is connected to the first AC terminal; the zero-crossing pulse output by the zero-crossing pulse output terminal is a positive pulse; the The zero-crossing pulse corresponds to the positive half-wave of the second AC power supply; the width of the zero-crossing pulse is smaller than the positive half-wave width of the second AC power supply; the positive half-wave of the second AC power supply is that the potential of the first AC terminal is higher than that of the second the second AC mains half-wave of the AC terminal potential; The speed given module is provided with a speed given signal output terminal and a direction given signal output terminal; The single-chip microcomputer control module includes a speed given signal input end, a direction given signal input end, a capture signal input end and two-way level signal output ends; the speed given signal input end is connected to the speed of the given speed module. given signal output terminal; the direction given signal input terminal is connected to the direction given signal output terminal of the speed given module; the capture signal input terminal is connected to the zero-crossing pulse output terminal of the zero-crossing detection module; the two The circuit level signal output terminals are respectively the AC control output terminal and the rectification control output terminal; the AC control output terminal and the rectification control output terminal are respectively connected to the AC control input terminal and the rectification control input terminal of the trigger control module; The speed adjustment unit is composed of an adjustable power supply module, a waveform sampling module, a single-chip microcomputer adjustment module, and a motor drive module; the adjustable power supply module inputs a controllable rectified voltage and outputs a second DC working power supply, and is composed of a single-phase rectifier bridge and a second DC working power supply. Two filtering and voltage stabilizing circuits; the rectifying negative terminal of the single-phase rectifying bridge of the regulating power supply is a reference ground; the second DC working power outputted by the regulating power supply module supplies power to the single-chip microcomputer regulating module; The waveform sampling module is provided with a sampling waveform input terminal and a sampling pulse output terminal; the sampling waveform input terminal is connected to the second controllable rectification input terminal; the waveform sampling module makes the potential of the second controllable rectification input terminal higher than the first Detecting and limiting the potential waveform of a controllable rectification input terminal to obtain a sampling pulse; the positive pulse of the sampling pulse corresponds to the waveform whose potential of the second controllable rectification input terminal is higher than the potential of the first controllable rectification input terminal; The single-chip microcomputer adjustment module has a capture input end, a speed adjustment output end, a direction control output end, and a braking control output end; the capture input end of the single-chip microcomputer adjustment module is connected to the sampling pulse output end of the waveform sampling module; The motor drive module is used to drive a DC brushless motor, and is provided with a speed adjustment input end, a direction control input end, and a brake control input end; the speed adjustment input end is connected to the speed adjustment output end of the single-chip microcomputer adjustment module, and the direction control The input end is connected to the direction control output end of the single-chip microcomputer adjustment module, and the brake control input end is connected to the brake control output end of the single-chip microcomputer adjustment module; The rectification control unit sends a speed control signal by controlling the controllable rectification voltage, and the speed control signal is composed of a pilot wave and a data wave; The guide wave is composed of a rectification wave of y-1 power frequency period and an AC wave of 1 power frequency period, the rectification wave is in front and the AC wave is in the back; y is an integer greater than or equal to 2; The data wave is a controllable rectified voltage wave of x power frequency periods, and x is an integer greater than or equal to 2; The speed control signal has a total speed of 1-n, and a total of n speed levels; the speed level of the speed given signal has a speed of 1-n; n is an integer greater than or equal to 2; Among the controllable rectification voltage waves of x power frequency cycles, 1 power frequency cycle corresponds to 1-bit data code; the controllable rectification voltage wave of x power frequency cycles corresponds to x-bit data code; The x-bit data code includes x-1-bit speed code and 1-bit direction code; the relationship between n and x is: n is less than or equal to 2 ^x-1 ; The data code, speed code and direction code are all binary codes; The method that described single-chip microcomputer control module sends a speed control signal is, Step 1, wait until the rising edge of the zero-crossing pulse is received and enter step 2; Step 2, stop the AC output and start the rectification output; Step 3, count the rising edge of the received zero-crossing pulse, and enter step 4 when the count value reaches y-1; Step 4, stop the rectification output and start the AC output; Step 5, wait until the rising edge of the zero-crossing pulse is received and enter step 6; Step 6, sending out a controllable rectified voltage wave of one power frequency cycle; Step 7, wait until the rising edge of the zero-crossing pulse is received and enter step 8; Step 8, go to step 9 when the controllable rectified voltage wave of x power frequency periods has been issued, otherwise return to step 6; Step 9, stop the rectification output and start the AC output; The method of sending the speed control signal by the rectification control unit is: Step A, read a given signal; Step B, sending out a speed control signal; Step C, judge whether the speed has changed, if the speed has changed, return to step B; if the speed has not changed, return to step C; The method for the speed adjustment unit to receive the speed control signal and adjust the speed of the brushless DC motor is: Step 1, motor control initialization, set the brushless DC motor to the braking state; Step 2, judge whether there is a speed control signal; if there is no speed control signal, return to step 2; if there is a speed control signal, go to step 3; Step 3, receiving a speed control signal; Step 4, adjust the speed of the brushless DC motor; return to step 2. 2. The method for long-distance speed regulation of a brushless DC motor according to claim 1, wherein the method of judging whether there is a speed control signal is judging whether there is a guide wave in the controllable rectified voltage. 3. The method for long-distance speed regulation of a brushless DC motor according to claim 2, characterized in that: the method for judging whether there is a guide wave in the controllable rectified voltage is after judging the power frequency period rectangular wave in the sampling pulse The number of power frequency cycles in the low-level interval exceeding the width of the power frequency cycle; if there is a low-level interval with a power frequency cycle number of y-1 in the sampling pulse after the power frequency cycle rectangular wave, then there is a pilot wave in the controllable rectified voltage ; There is no low-level interval with a power frequency cycle number of y-1 in the sampling pulse after the power frequency cycle rectangular wave, and there is no guide wave in the controllable rectified voltage. 4. The method for long-distance speed regulation of a brushless DC motor according to claim 3, characterized in that: the number of power frequency cycles in the low-level interval exceeding the power frequency cycle width after the power frequency cycle rectangular wave in the judgment sampling pulse The method is to measure the width of the low-level pulse that exceeds the width of the power frequency cycle after the rectangular wave of the power frequency cycle in the sampling pulse, and assume that the measured low-level pulse width exceeding the width of the power frequency cycle is W, then the low-level pulse The number of power frequency cycles in the interval is INT(W/20); the function of the INT function is to round off the decimal part. 5. The method for long-distance speed regulation of a brushless DC motor according to claim 1, characterized in that: the method of receiving the speed control signal is to receive the controllable rectified voltage wave of x power frequency cycles and convert it into x bits Data code, convert the x-bit data code into speed code and direction code, and convert the speed code into the speed level of the speed control signal. 6. The method for long-distance speed regulation of a brushless DC motor according to claim 5, characterized in that: the controllable rectified voltage wave receiving x power frequency cycles is converted into x-bit data codes, the method is: In the x power frequency period intervals after the guide wave, when the sampling pulse of 1 power frequency period interval is low level, the corresponding bit data code is 1, when the sampling pulse of 1 power frequency period interval is 1 When the duty cycle is less than 50% of the rectangular wave, the corresponding bit data code is 0; The method is either: In the x power frequency period intervals after the guide wave, when the sampling pulse of 1 power frequency period interval is low level, the corresponding data code of this bit is 0, when the sampling pulse of 1 power frequency period interval is 1 When the duty cycle is less than 50% of the rectangular wave, the corresponding data code of this bit is 1. 7. The method for long-distance speed regulation of a brushless DC motor according to claim 1, characterized in that: said stopping the AC output refers to controlling the output of the AC control output terminal to output an invalid signal; said starting the rectification output refers to controlling The rectification control output terminal outputs a valid signal; the start of the AC output refers to controlling the AC control output terminal to output a valid signal; the stop of the rectification output refers to the control of the rectification control output terminal to output an invalid signal. 8. The method for long-distance speed regulation of brushless DC motors according to claim 1, characterized in that: the method for judging whether the speed changes is that the speed level of the speed given signal changes, or the direction given signal changes, the speed changes. 9. The method for remote speed regulation of a brushless DC motor according to claim 1, characterized in that: when the speed level of the speed control signal is level 1, the brushless DC motor is controlled to brake. 10. The method for remote speed regulation of a brushless DC motor according to claim 1, wherein the power frequency period is 20 ms.