KR100635006B1 - System for driving a permanent magnet brushless direct currentPM BLDC motor and driving method thereof - Google Patents

Abstract

The drive device of the PM BLDC motor using the three harmonics according to the present invention, the rectifier for receiving a single-phase AC power to convert the DC to output; An inverter converting the DC power input from the rectifier into a three-phase AC power and providing the same to the PM BLDC motor; A third harmonic detection circuit unit connected to each of the three-phase lines connecting the inverter and the PM BLDC motor by Y-connections and detecting a third harmonic voltage of the PM BLDC motor; A hysteresis current control unit connected to any two phases of a three-phase line connecting the inverter and the PM BLDC motor, and detecting hysteresis current by detecting the connected two-phase currents; A Hall sensor signal generation unit receiving an output signal from the third harmonic detection circuit unit and the hysteresis current control unit and generating an estimated Hall sensor signal; A gate driver configured to receive an output signal from the hall sensor signal generator and generate a gate signal for driving a gate terminal of the semiconductor switching device in the inverter; And a hysteresis current controller and a hall sensor signal generator, electrically outputting a driving start signal of the hall sensor signal generator, and receiving a hall sensor signal from the hall sensor signal generator to control PI and D / A. And a main controller to output a control signal for controlling the hysteresis current controller.

Description

System for driving a permanent magnet brushless direct current (PM BLDC) motor and driving method

1 is a view schematically showing a system configuration of a driving device of a PM BLDC motor using three harmonics according to the present invention.

Figure 2 is a view showing the internal configuration and the third harmonic detection overview of the inverter of the drive device of the PM BLDC motor using three harmonics according to the present invention.

3 is a view showing a process of generating a switching signal using the third harmonic according to the driving method of the PM BLDC motor using the three harmonics according to the present invention.

4 is a view illustrating a configuration of a hall sensor signal generation circuit (block) provided inside a hall sensor signal generator in a driving device of a PM BLDC motor using three harmonics according to the present invention;

FIG. 5 is a diagram illustrating a Hall sensor signal generation algorithm by the Hall sensor signal generation circuit (block) of FIG. 4.

6 is a view showing a process of generating a six-pulse signal using a Hall sensor signal according to the driving method of a PM BLDC motor using three harmonics according to the present invention.

7 shows an initial driving algorithm of a PM BLDC motor.

<Explanation of symbols for the main parts of the drawings>

110 ... rectifier 120 ... inverter

130 ... 3 Harmonic Detection Circuit Unit 140 ... Hysteresis Current Control Unit

150 ... hall sensor signal generator 160 ... gate driver

170.Main control unit

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a driving device and a driving method of a motor using a PM harmonic (PM BLDC) motor, which is commonly referred to as 'PM BLDC'. By utilizing the third harmonic component of the voltage in the control mechanism for driving the motor, it is not sensitive to the delay caused by the filter and has a good performance in a wide range of speed. It is about.

Today, the use of brushless servo motors in which rotors are composed of permanent magnets is increasing in various industrial and automation devices.

The operation of the PM BLDC motor must first know the position of the rotor. Rotor position sensor, encoder and resolver are mainly used to know the position of the rotor made of permanent magnets and are used to rectify the phase current of the PM BLDC motor. This approach has several problems, such as increased costs, increased volume, and environmental constraints. Therefore, in recent years, research into the sensorless driving method has been actively conducted.

The present invention has been made in view of the above-mentioned matters, and by utilizing the third harmonic component of the terminal voltage in the control mechanism for driving the motor among various sensorless driving methods, it is not sensitive to delay caused by the filter and has a wide speed. It is an object of the present invention to provide a driving device and a driving method of a PM BLDC motor using three harmonics having good performance in a range.

In order to achieve the above object, the drive device of a PM BLDC motor using three harmonics according to the present invention,

A rectifier for receiving single-phase AC power and converting the signal into direct current;

An inverter converting the DC power input from the rectifier into a three-phase AC power and providing the same to a PM BLDC motor;

A third harmonic detection circuit unit connected to each of the phases of the three-phase line connecting the inverter and the PM BLDC motor and detecting a third harmonic voltage of the PM BLDC motor;

A hysteresis current control unit connected to any two phases of a three-phase line connecting the inverter and the PM BLDC motor, and detecting hysteresis current by detecting the connected two-phase currents;

A Hall sensor signal generator which receives an output signal from the third harmonic detection circuit unit and a hysteresis current controller and generates an estimated Hall sensor signal identical to a signal generated from a hall sensor attached to a conventional PM BLDC motor;

A gate driver configured to receive an output signal from the hall sensor signal generator and generate a gate signal for driving a gate terminal of a semiconductor switching element in the inverter; And

It is electrically connected to the hysteresis current controller and the Hall sensor signal generator, and outputs the driving start signal of the Hall sensor signal generator, and receives the Hall sensor signal from the Hall sensor signal generator to perform PI control and D / A control. And a main controller for outputting a control signal for controlling the hysteresis current controller and exchanging information related to driving of the PM BLDC motor with an external computer system.

In addition, the method of driving a PM BLDC motor using three harmonics according to the present invention in order to achieve the above object,

A rectifier for converting and outputting an input AC power into a DC, an inverter for converting and outputting a DC power input from the rectifier into a three-phase AC power, a third harmonic detection circuit for detecting a third harmonic of a PM BLDC motor, and a PM BLDC motor A hysteresis current controller for controlling the hysteresis current of the inputted current, a Hall sensor signal generator for generating an estimated Hall sensor signal using the third harmonic, and a gate signal for driving the gate terminal of the semiconductor switching element in the inverter. The PM BLDC motor is driven by a drive device of a PM BLDC motor using three harmonics, which has a main controller that receives a generated gate driver and a Hall sensor signal from the Hall sensor signal generator and performs PI control and D / A control. In the method,

a) detecting a third harmonic voltage of the PM BLDC motor by measuring a voltage between the neutral point inside the PM BLDC motor and the neutral point of the Y-connection of the third harmonic detection circuit portion;

b) integrating the detected third harmonic voltage by the Hall sensor signal generator to obtain a 90 ° delayed waveform, and again generating a commutation signal through a zero voltage detection circuit;

c) generating an estimated Hall sensor signal of each phase of the PM BLDC motor by the Hall sensor signal generator using the generated switching signal;

d) generating a six-pulse signal by the Hall sensor signal generator using the estimated Hall sensor signal of each phase and outputting a signal for driving the gate driver; And

e) using the generated 6-pulse signal to determine the position and speed of the rotor of the PM BLDC motor by the main controller, while performing PI control and D / A control to control the hysteresis current control unit It is characterized in that it comprises the step of driving the PM BLDC motor by outputting.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a diagram schematically illustrating a system configuration of a driving device of a PM BLDC motor using three harmonics according to the present invention.

Referring to FIG. 1, a driving device of a PM BLDC motor using three harmonics according to the present invention includes a rectifier 110, an inverter 120, a third harmonic detection circuit unit 130, a hysteresis current controller 140, and a hall sensor signal. The generator 150 includes a gate driver 160 and a main controller 170.

The rectifier 110 receives the single-phase AC power supply 100 and converts it into direct current. Such a rectifier 110 may be configured as a bridge circuit consisting of four diodes.

The inverter 120 converts the DC power input from the rectifier 110 into a three-phase AC power and provides it to the PM BLDC motor 135. As shown in FIG. 2, the inverter 120 is a series / parallel combination circuit of six unit switching circuits SW1 to SW6 in which diodes are connected in reverse parallel to six semiconductor switching elements (eg, IGBTs). It can be configured as.

The third harmonic detection circuit 130 is connected to the Y-connection of each phase of the three-phase line connecting the inverter 120 and the PM BLDC motor 135, the third harmonic voltage of the PM BLDC motor 135 Is detected. The third harmonic detection circuit unit 130 is formed by connecting three resistors having the same value to each of the three-phase lines connecting the inverter 120 and the PM BLDC motor 135 by Y-connections.

The hysteresis current controller 140 is connected to any two phases of the three-phase line connecting the inverter 120 and the PM BLDC motor 135, and detects the connected two-phase currents to control the hysteresis current. .

The hall sensor signal generation unit 150 receives output signals from the third harmonic detection circuit unit 130 and the hysteresis current control unit 140 and is identical to a signal generated from a hall sensor attached to a conventional PM BLDC motor. Generate an estimated Hall sensor signal. Here, the Hall sensor signal generation unit 150 is composed of an EPLD (Erasable Programmable Logic Device), although not shown in detail in this drawing, the inverter switching portion and the third harmonic detection circuit portion ( A part for generating a Hall sensor signal of each phase using the three harmonic signals detected by 130) and a six pulse generating part for generating a pulse at an interval of 60 ° using the generated Hall sensor signal are provided.

The gate driver 160 receives an output signal from the hall sensor signal generator 150 and generates a gate signal for driving the gate terminal of the semiconductor switching device in the inverter 120.

The main controller 170 is electrically connected to the hysteresis current controller 140 and the hall sensor signal generator 150, outputs a driving start signal of the hall sensor signal generator 150, and generates a hall sensor signal. Receives a Hall sensor signal from the unit 150 to perform PI (proportional and integral) control and digital-to-analog (D / A) control, and outputs a control signal for controlling the hysteresis current controller 140. On the other hand, the external computer system 175 exchanges information related to the operation of the PM BLDC motor 135. Here, the main controller 170 receives a reference speed and an actual measurement speed, receives a PI controller 172 that performs proportional and integral control, and an output of the PI controller 172 to receive a D / A ( The D / A controller 174 which performs digital-to-analog) control and 6 pulses generated using the Hall sensor signal from the Hall sensor signal generator 150 are input to receive the PM BLDC motor 135. A counter 176 is built in to calculate the actual speed.

Then, the driving method of the PM BLDC motor by the driving device of the PM BLDC motor using the three harmonics according to the present invention having the configuration as described above will be described.

In order to drive the PM BLDC motor 135, first, the position of the rotor of the motor 135 needs to be detected. Conventional conventional methods for detecting the position of the rotor have been provided with a Hall sensor inside the PM BLDC motor 135, or other encoders or resolvers. However, in the present invention, as described above, a method of indirectly detecting the position of the rotor using the third harmonic voltage component of the PM BLDC motor 135, rather than using such a separate rotor position sensing means. Take it.

Therefore, first, the third harmonic voltage component is detected. For this purpose, as shown in FIG. 2, the neutral point m inside the PM BLDC motor 135 and the Y-connection of the third harmonic detection circuit 130 is detected. The third harmonic voltage of the PM BLDC motor 135 is detected by measuring the voltage Vmn between the neutral points n.

Here, Kirchhoff's voltage equation (KVL) is applied to analyze the voltage Vn of the terminal n as follows.

는 다음과 같이 나타낼 수 있다.In addition, from FIG.

Can be expressed as:

Equations 1 and 2 are summarized as follows.

The third harmonic voltage component obtained as described above has the position information of the rotor.

Accordingly, as shown in FIG. 3, the detected third harmonic voltage is integrated by the Hall sensor signal generator 150 to obtain a 90 ° delayed waveform (integrated signal waveform), and the zero voltage detection circuit is again obtained. It generates a commutation signal.

When the switching signal is generated in this way, the Hall sensor signal generator 150 estimates the Hall sensor signals H _A , H _B , H _C of each phase of the PM BLDC motor 135 by using the generated switching signal. Create That is, the Hall sensor generation circuit (block diagram) using the Johnson counter provided in the Hall sensor signal generator 150 as shown in FIG. 4 and the Hall sensor signal generation algorithm using the EPLD as shown in FIG. Finally, the estimated Hall sensor signals H _A , H _B and H _C of each phase are generated.

When the estimated Hall sensor signals H _A , H _B and H _C of each phase are generated by the above, as shown in FIG. 6, the estimated Hall sensor signals H _A , H _B , H _{C of} the generated phases of each phase are generated. By generating a six-pulse signal by the Hall sensor signal generator 150, and outputs a signal for driving the gate driver 160. That is, by using the Hall sensor signal generated by the Hall sensor generating circuit (block) of FIG. 4, the pulse signal is generated every 60 ° by detecting the rise time and the fall time of each signal, thereby generating six pulses per rotation of 360 °. To generate a pulse signal.

When the 6-pulse signal is generated in this way, the position and speed of the rotor of the PM BLDC motor 135 are determined by the main controller 170 using the generated 6-pulse signal, while the PI control and D / A The PM BLDC motor 135 is driven by performing a control to output a signal for controlling the hysteresis current controller 140.

Here, in relation to the driving method of the PM BLDC motor 135 of the present invention as described above, the description will be added to the initial driving method of the PM BLDC motor 135 prior to the full-scale driving of the PM BLDC motor 135. do.

One problem in the sensorless operation of the PM BLDC motor 135 is that the position of the initial rotor in the stationary state is unknown. As a method for detecting the initial rotor position, the present invention uses a forced alignment method in which two phases are forcibly excited to align the rotor to a specified position. When aligning forcedly, pay attention to the inertia of the motor, the size of the load, etc., and allocate sufficient alignment time if necessary to proceed to the next step.

However, if the forced alignment is performed for longer than necessary or if forced alignment is applied by applying more voltage than necessary, the permanent magnet rotor may be depleted due to excessive current flowing through the stator winding. Should be selected.

When forced alignment is normally performed, the rotor is aligned with the designated phase, and the controller operates by exciting the next phase sequentially. In the sensorless operation of the present invention, since the sensorless operation is unstable with the detected signal until reaching a certain speed, acceleration to an area where a stable rotor position information signal can be detected is essential. This acceleration behavior is called synchronous acceleration. The initial synchronous acceleration is based on the forced alignment phase, and the input voltage that should be increased according to the acceleration state and speed is based on the results obtained through experiments. You must specify this in advance.

In particular, when a sudden change in load occurs during synchronous acceleration, synchronous acceleration may fail or synchronous acceleration itself may become impossible. Therefore, the acceleration algorithm should be written to repeat the experiment in various environments to overcome the widest load area.

7 is a diagram illustrating an initial driving algorithm of a PM BLDC motor.

Referring to FIG. 7, the initial driving of the PM BLDC motor is composed of three operation modes, namely, mode 1, mode 2, and mode 3.

Mode 1 is a mode of forced alignment in which the two phases are forcibly excited in the initial alignment mode so that the rotor is aligned with the specified phase at any position.

In the mode 2, when the forced alignment is normally performed in the synchronous acceleration mode, the rotor is aligned with the designated phase, and the controller starts the operation by exciting the next phase sequentially. In the sensorless operation of the present invention, since it is impossible to perform the sensorless operation with the indirectly detected signal until a certain speed is reached, it is a mode for accelerating to an area where a reliable rotor position information signal can be detected.

Mode 3 is a mode for driving a PM BLDC motor using a switching signal generated by three harmonics detected according to the motor driving method of the present invention and a Hall-ICs signal generated using the switching signal. to be.

As described above, the driving device of the PM BLDC motor using three harmonics and the driving method thereof according to the present invention do not install a hall sensor inside the PM BLDC motor and use the detection signal by the hall sensor. 3 Harmonic voltage is detected and used to generate an estimated Hall sensor signal corresponding to the detected signal by the Hall sensor to determine the rotor position and to control the speed of the motor. .

First, since Hall sensors (Hall-ICs), which were previously required for speed control, are not required, there is an advantage of lowering the overall driving circuit price.

Second, the sensorless operation using the third harmonic signal does not require a phase delay filter and determines the switching time of the current in hardware, thereby reducing the burden on the sensorless drive processor.

Third, since the counter electromotive force waveform and the phase current can maintain a relatively accurate synchronization, stable sensorless operation is possible in a wide speed range.

Claims (7)

A rectifier for receiving single-phase AC power and converting the signal into direct current; An inverter converting the DC power input from the rectifier into a three-phase AC power and providing the same to a PM BLDC motor; A third harmonic detection circuit unit connected to each of the phases of the three-phase line connecting the inverter and the PM BLDC motor and detecting a third harmonic voltage of the PM BLDC motor; A hysteresis current controller connected to any two phases of a three-phase line connecting the inverter and the PM BLDC motor, and detecting hysteresis current by detecting the connected two-phase currents; A Hall sensor signal generator which receives an output signal from the third harmonic detection circuit unit and a hysteresis current controller and generates an estimated Hall sensor signal identical to a signal generated from a hall sensor attached to a conventional PM BLDC motor; A gate driver configured to receive an output signal from the hall sensor signal generator and generate a gate signal for driving a gate terminal of a semiconductor switching element in the inverter; And It is electrically connected to the hysteresis current controller and the Hall sensor signal generator, and outputs the driving start signal of the Hall sensor signal generator, and receives the Hall sensor signal from the Hall sensor signal generator to perform PI control and D / A control. And a main control unit for outputting a control signal for controlling the hysteresis current control unit and exchanging information related to the operation of the PM BLDC motor with an external computer system. Drive system. The method of claim 1, The inverter is a drive device for a PM BLDC motor using three harmonics, characterized in that the diode is connected to the six semiconductor switching elements each of the parallel / parallel combination circuit of six unit switching circuits. The method of claim 1, The third harmonic detection circuit part of the PM BLDC motor using three harmonics is characterized by connecting three resistors having the same value to each of the three-phase lines connecting the inverter and the PM BLDC motor by Y-connections. Drive system. The method of claim 1, Inside the hall sensor signal generator, an inverter switching part, a part generating a hall sensor signal of each phase using the third harmonic signal detected by the third harmonic detection circuit part, and 60 ° using the generated hall sensor signal. A drive device for a PM BLDC motor using three harmonics, characterized in that a six-pulse generation portion is provided to generate pulses at intervals. The method of claim 1, The main control unit receives a reference speed and an actual measurement speed, and performs a PI (proportional and integral) control, and a D / A (digital-to-analog) control that receives the output of the PI controller. PM BLDC motor using three harmonics, A controller and a counter that calculates the actual speed of the PM BLDC motor by receiving the six pulses generated by using the Hall sensor signal from the Hall sensor signal generator. Drive. A rectifier for converting and outputting an input AC power into a DC, an inverter for converting and outputting a DC power input from the rectifier into a three-phase AC power, a third harmonic detection circuit for detecting a third harmonic of a PM BLDC motor, and a PM BLDC motor A hysteresis current controller for controlling the hysteresis current of the current inputted to the input signal, a Hall sensor signal generator for generating an estimated Hall sensor signal using the third harmonic, and a gate signal for driving the gate terminal of the semiconductor switching element in the inverter. The PM BLDC motor is driven by a drive device of the PM BLDC motor using three harmonics, which has a main controller that receives the generated gate driver and the Hall sensor signal from the Hall sensor signal generator and performs PI control and D / A control. In the method, a) detecting a third harmonic voltage of the PM BLDC motor by measuring a voltage between the neutral point inside the PM BLDC motor and the neutral point of the Y-connection of the third harmonic detection circuit portion; b) integrating the detected third harmonic voltage by the Hall sensor signal generator to obtain a 90 ° delayed waveform, and again generating a commutation signal through a zero voltage detection circuit; c) generating an estimated Hall sensor signal of each phase of the PM BLDC motor by the Hall sensor signal generator using the generated switching signal; d) generating a six-pulse signal by the Hall sensor signal generator using the estimated Hall sensor signal of each phase and outputting a signal for driving the gate driver; And e) using the generated 6-pulse signal to determine the position and speed of the rotor of the PM BLDC motor by the main controller, while performing PI control and D / A control to control the hysteresis current control unit Driving a PM BLDC motor using three harmonics, characterized in that it comprises the step of driving the PM BLDC motor by outputting. The method of claim 6, Forcibly exciting any two phases of the PM BLDC motor as an initial driving step prior to detecting the third harmonic voltage in step a) to force alignment of the rotor to align with the specified phase. And accelerating the rotor until reaching a constant speed by sequentially exciting the next phase when forced alignment is normally performed. 3. The method of driving a PM BLDC motor using three harmonics.

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