JP4558862B2 - Drive system and method for inverter system - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an inverter driving device and a driving method thereof, and more specifically, by selectively operating a PAM (Pulse Amplitude Modulation) function, an initial stage of power application, an initial driving stage of the inverter apparatus, and a PAM. An inverter power factor correction device that can solve the interference problem that occurs around the switching element when driving the switching element to drive the PAM function more efficiently and economically, and when the inverter and the load are driven, the input voltage and the input current Inverter system power factor correction device and its method that can drive the inverter efficiently and economically only when the waveform is in phase, especially when the PAM function works, drive the inverter and load to reduce noise When the power supply voltage is low, only inverter and load control that prioritize efficiency are performed. And it relates to an inverter system power factor correction container storage and method thereof.
[0002]
[Prior art]
Recently, inverters have been developed in many parts of home appliances from the viewpoint of energy saving and ease of output control. For example, washing machines and refrigerators using a motor driven by an inverter have been developed and released. It's getting on.
In the conventional inverter device, as shown in FIG. 6, a rectifying unit 11 for rectifying an input commercial AC power source into a DC voltage by a diode bridge, and a choke for smoothing and outputting the voltage output from the rectifying unit 11 A coil 12 and a smoothing capacitor 13 and an inverter 14 for driving a motor M by converting a DC voltage smoothed by the choke coil 12 and the smoothing capacitor 13 into a three-phase AC power source again by pulse width modulation (PWM). And was configured to include.
[0003]
Hereinafter, the operation of the conventional inverter device configured as described above will be described with reference to FIG.
First, when an AC power supply having a voltage waveform of the commercial AC power supply as shown in FIG. 7A and a current waveform of the commercial AC power supply as shown in FIG. The unit 11 rectifies the DC voltage using a diode bridge, and then outputs the rectified voltage to the choke coil 12.
[0004]
Then, the choke coil 12 and the smoothing capacitor 13 output to the inverter 14 a DC voltage from which an AC component included in the DC voltage output from the rectifying unit 11 has been removed.
At this time, the DC voltage input to the inverter 14 is larger than the peak value of the input AC power supply.
[0005]
Therefore, the inverter 14 converts the DC voltage input from the smoothing capacitor 13 into a three-phase AC power supply by the on / off operation of the switching element and supplies it to the motor M to drive the motor.
In FIG. 7B, the time t is a time determined by the time constants of the choke coil 12 and the smoothing capacitor 13, and is usually 1/5 or less of the commercial AC power supply.
[0006]
Here, assuming that the power factor is 1, the current waveform flowing through the inverter has the same phase as that of the commercial AC power input, and as shown in FIG. 7C, the peak current is extremely smaller than the maximum current value. In order to form an ideal current waveform having a noise, there is an effect that noise and reactive power are reduced. In developed countries, the formation of a waveform as shown in FIG. A method of applying a power factor correction circuit to the inverter system has been adopted.
[0007]
In the conventional power factor correction apparatus for an inverter system, as shown in FIG. 8, a rectifying unit 100 for rectifying a commercial AC power supply AC, a choke coil L1 for smoothing the output voltage of the rectifying unit 100, and the choke coil The output voltage of L1 is input through the rectifying diode D1, and the smoothing capacitor C1 for re-smoothing, the control unit 130 for outputting the PAM drive control signal in response to the setting to the PAM mode by the user, the collector Is connected to the subsequent stage of the choke coil L1, the emitter is grounded, and the PAM control transistor N1 whose conduction is controlled by applying the PAM drive control signal from the control unit 130 to the base, and the DC of the smoothing capacitor C1 An inverter 110 for converting the voltage into a variable frequency and a variable voltage by pulse width modulation (PWM); A motor 120 driven by the control of the converter unit 110, has been configured with a.
[0008]
Hereinafter, the operation of the power factor correction device of the conventional inverter device configured as described above will be described.
First, the rectifying unit 100 receives and rectifies the input of the commercial AC power supply AC, and outputs the rectified voltage. The choke coil L1 and the smoothing capacitor C1 apply a DC voltage obtained by smoothing the rectified signal of the rectifying unit 100 to the inverter unit 110. The inverter unit 110 drives the motor 120 by converting the DC voltage of the smoothing capacitor C1 into variable frequency and variable voltage by pulse width modulation.
[0009]
At this time, the control unit 130 controls on / off of the PAM control transistor N1 so that the power supplied to the load (motor) is in the same phase as the input commercial AC power AC, and from the maximum current value of the commercial AC power AC. Also correct the power factor to have a small peak current.
The power factor improving circuit of the conventional inverter system will be described in more detail. As shown in FIG. 9, a rectifying unit 31 that rectifies an input commercial AC power source into a DC voltage by a diode bridge, and is output from the rectifying unit 31. The choke coil 32 and the smoothing capacitor 33 for smoothing and outputting the voltage to be output and the DC voltage smoothed by the choke coil 32 and the smoothing capacitor 33 to the three-phase AC power source again by pulse width modulation (PWM). The inverter 36 that converts and drives the motor M, and the output voltage of the rectifying unit 31 and the voltage applied to both stages of the smoothing capacitor 33 are compared using the comparator, multiplexer, NAND gate, NOR gate, etc. Analog power factor correction unit that varies the pulse width duty to match the typical input current and voltage 4 and a switching element Q1 that is turned on / off by the pulse width duty varied by the analog power factor improvement unit 34 and controls the charge / discharge operation of the smoothing capacitor 33, and corrects the power factor. And a portion 35.
[0010]
Hereinafter, the operation of the power factor correction circuit of the conventional inverter system configured as described above will be described with reference to FIGS.
First, when a commercial AC power supply is applied to the power factor correction device, the rectification unit 31 rectifies and outputs a DC voltage, and the DC voltage output in this way is caused by the resistors R1 and R2 of the power factor correction unit 35. After being divided, the voltage is input to the third terminal VM1 of the analog power factor correction unit 34.
[0011]
On the other hand, the voltage induced by the choke coil 32 is input to the fifth terminal Idet of the analog power factor correction unit 34 via the resistor R5, and the voltage induced by the choke coil 32 is the resistor R4, the diode D1, and The voltage adjusted by the capacitor C1 and the voltage adjusted by the resistor R3 are added and input to the eighth terminal VCC of the analog power factor improvement unit 34. At this time, the reason why the input voltage is continuously received through the eighth terminal VCC is to form the same waveform as the waveform of the input voltage during the power factor control.
[0012]
The output voltage of the rectifying unit 31 is input to the inverter 36 via the choke coil 32 and the diode D2, and then divided by the resistors R11 to R13 to be a first terminal of the analog power factor improving unit 34. Further, the divided voltage is input to INV and adjusted by the time constant of the capacitor C2 and the resistors R7 and R8 and input to the second terminal COMP of the analog power factor correction unit 34, while the inverter 36 , That is, a voltage determined by the capacitor C <b> 3 is input to the fourth terminal CS of the analog power factor correction unit 34.
[0013]
Next, as shown in FIG. 10, the analog power factor improvement unit 34 includes comparators 341, 346, 349, a multiplexer 347, NAND gates 343, 344, a self-starter (SELF-STARTER) 342, and a NOR gate 345. The input voltage and the output voltage of the inverter 36 are compared with each other, and a pulse prepared so as to match the voltages is output. As shown in FIGS. Then, a pulse for increasing the duty and decreasing the duty at a high sine wave is output via the seventh terminal Vout.
[0014]
Next, the pulse output through the seventh terminal Vout of the analog power factor correction unit 34 is input to the gate of the switching element Q1, and the switching element Q1 is turned on / off in response to the pulse to input current and input. The power factor has been corrected to match the phase of the voltage.
[0015]
[Problems to be solved by the invention]
However, in such a power factor correction device of the conventional inverter system, since the PAM function cannot be selectively operated, it is generated in the periphery at the initial stage of power supply application, initial driving of the inverter motor, and driving of the PAM switching element. The interference problem cannot be appropriately dealt with, and since the analog system is used, the peripheral circuit is complicated and the signal control is difficult, so that the inverter and the load cannot be driven efficiently. There was a serious problem.
[0016]
The present invention has been made in view of such a conventional problem. By selectively operating the PAM function, the present invention occurs in the vicinity of the initial application of power, the initial drive of the inverter motor, and the drive of the PAM switching element. An object of the present invention is to provide a power factor correction device for an inverter system that can solve the interference problem and can efficiently and economically drive the PAM function.
[0017]
Another object of the present invention is to realize a soft start PAM drive circuit that can implement a PAM function efficiently by performing a signal control easily because the power factor correction circuit is digitally implemented. Try to provide a driving method.
Another object of the present invention is to drive economically by initially driving with the PAM function and driving the inverter and load only when the waveforms of the input current and input voltage are in phase and reducing noise. It is an object of the present invention to provide a method for driving a soft start pamm driving circuit.
[0018]
Another object of the present invention is to drive the inverter and the load only when the input current and the input voltage are in phase with the PAM function in the initial stage, and to improve the efficiency when the power supply voltage is low. A drive method of a soft start PAM drive circuit capable of controlling only the inverter and the load to be prioritized is to be provided.
[0019]
[Means for Solving the Problems]
In order to achieve such an object, in a power factor correction apparatus for an inverter system according to the present invention, a rectifier that rectifies a commercial AC power supply, a choke coil that smoothes the output voltage of the rectifier, A smoothing capacitor that receives an output voltage via a rectifying diode and further smoothes, a collector is connected to the subsequent stage of the choke coil, an emitter is grounded, and a PAM drive control signal is applied to the base to control conduction. And a control unit that outputs a PAM drive control signal and a relay drive control signal in response to a user setting the PAM mode in an inverter system including a control transistor, and relay drive control of the control unit A relay drive unit that receives a signal input and outputs a relay drive signal, and a drive signal of the relay drive unit. And it is configured to encompass a relay for selecting the PAM mode or normal mode, the.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
In the first embodiment of the power factor correction apparatus for an inverter system according to the present invention, as shown in FIG. 1, a rectifying unit 100 for rectifying a commercial AC power supply AC and a choke for smoothing the output voltage of the rectifying unit 100 The coil L1, the output voltage of the choke coil L1 is input via the rectifying diode D1, and the smoothing capacitor C1 is re-smoothed. When the PAM mode is set by the user, the PAM drive control signal and the relay drive control A control unit 200 for outputting a signal, a collector is connected to the subsequent stage of the choke coil L1, an emitter is grounded, and a PAM drive control signal of the control unit 200 is applied to the base to control conduction. The first input stage NC is connected to the preceding stage of the choke coil L1, and the second input stage NO is connected to the PAM control traffic. The relay 220 is connected to the collector of the transistor N1 and is switched to the first input stage NC or the second input stage NO by the relay drive signal, and the relay drive control signal is input from the control unit 200, thereby the relay drive signal And a relay drive unit 210 for outputting.
[0021]
Here, the relay driver 210 is connected in parallel with an NPN transistor N2 that is ON / OFF controlled by a relay drive control signal of the controller 200, and a reverse current prevention diode D2, and the NPN transistor N2 is ON. A relay excitation coil L2 that is excited when
Hereinafter, the operation of the power factor correction apparatus for an inverter system according to the present invention configured as described above will be described.
[0022]
First, the general operation is the same as the conventional one. That is, the rectifying unit 100 rectifies the input commercial AC power supply AC, and the choke coil L1 and the smoothing capacitor C1 smooth the rectified signal of the rectifying unit 100 and apply a corresponding DC voltage to the inverter unit 100. Then, the inverter unit 110 converts the DC voltage of the smoothing capacitor C1 into a variable frequency and a variable voltage through pulse width modulation, and drives the motor 120. Here, the control unit 200 controls on / off of the PAM control transistor N1 so as to have the same phase as that of the input commercial AC power supply AC, and has a peak current smaller than the maximum current value of the commercial AC power supply AC. Correct the power factor.
[0023]
In the present invention, the PAM function is selectively operated by additionally including the relay 220 and the relay driving unit 210, and the peripherals are set at the initial stage of power application, the initial stage of motor driving, and the driving of the PAM switching element. It is possible to appropriately deal with the interference problem that occurs.
Here, as shown in FIG. 1, the first input stage NC of the relay 220 is connected to the preceding stage of the LI, and the second input stage NO is connected to the collector of the transistor N1 for PAM control, or One input stage NC can be connected to the subsequent stage of the choke coil L1 to select and switch the PAM mode.
[0024]
More specifically, when the relay 220 is set to be connected to the first input stage NC as shown in FIG. 1, when the user sets the PAM mode as necessary, the relay driving unit 210 controls the control unit 200. When a relay drive control signal is input from the relay 220, the relay 220 is switched to the second input stage NO by a corresponding relay drive signal to operate in the PAM mode, and when operating in the general mode, the contact of the relay 220 is set to the first contact. By switching to the input stage NC and directly rectifying the commercial power supply AC, drive control of a general motor 120 is performed.
[0025]
Here, the NPN transistor N2 of the relay driving unit 210 is turned on by the relay driving control signal of high potential to excite the relay exciting coil L2, and the relay 220 is switched to the second input stage NO to set the PAM mode. When a relay driving control signal having a low potential is input to the NPN transistor N1, the NPN transistor N1 is turned off to switch the relay 220 to the first input stage NC and set to the general mode. Here, the initial setting of the relay 220 is determined by the user.
[0026]
That is, according to the present invention, the relay 220 is switched to the first input stage NC or the second input stage NO by the user's selection to operate in the PAM mode or the general mode. In addition, it is possible to actively cope with the interference problem that occurs in the periphery when the PAM switching element is driven.
[0027]
And in 2nd Embodiment of the power factor correction apparatus of the inverter system which concerns on this invention, as shown in FIG. 2, it is a hybrid type inverter power factor correction apparatus.
The present invention, which operates in the PAM mode, includes a first stage in which the inverter and the load are initially driven by the PAM, and a first stage in which the input voltage and the input current are sensed after the PAM drive is performed for a predetermined time in the first stage. Two stages, a third stage for comparing the waveform of the input voltage and the input current sensed in the second stage, and driving the inverter and the load if the input voltage and the input current to be compared in the third stage are in phase, If not in phase, the fourth stage in which the inverter and the load are not driven is sequentially performed.
[0028]
Hereinafter, it will be described in detail with reference to the accompanying drawings.
FIG. 3 is a configuration diagram of an inverter system according to the present invention.
That is, a rectifying unit 61 that rectifies a commercial AC power source into a DC voltage via a diode bridge, a choke coil 62 and a smoothing capacitor 63 that smooth the output voltage and output, and a DC through the choke coil 62 and the smoothing capacitor 63. A voltage is converted into a three-phase AC power source by pulse width modulation (PWM) and connected in parallel to an inverter 64 for driving the motor M and a preceding stage of the smoothing capacitor 63, and the smoothing capacitor is turned on and off by an on / off operation. A switching element Q1 that adjusts a current flowing through the capacitor 63 and a voltage supplied to the inverter and the load 64 to perform PAM driving, an input voltage sensing unit 66 that senses an input voltage of an input commercial power source, and an input An input current sensing unit 67 for sensing current, and a waveform of the sensed input voltage and direct current. And compare is configured to include a control unit for driving the inverter and the load by turning on / off the switching element Q1 only when it becomes in phase.
[0029]
In the driving process of the inverter system according to the present invention, as shown in FIG. 5, first, the first stage in which the inverter and the load are driven by the PAM in the initial stage, and the PAM driving is performed for a predetermined time in the first stage. Then, the second stage for sensing the input voltage and the input current, the third stage for comparing the input voltage sensed in the second stage and the waveform of the input current, and the input voltage and the input compared in the third stage. If the current is in phase, the inverter and the load are driven, and if not in phase, the inverter and the load are not driven.
[0030]
Hereinafter, the operation and effect of the inverter system according to the present invention configured as described above will be described in detail.
First, when a commercial AC power supply is input, this is input to the rectifying unit 61 and a rectified DC voltage is output.
Then, the choke coil and the smoothing capacitor 63 limit the input voltage so that a necessary current flows, and the input voltage is smoothed and supplied by the inverter / load 64.
[0031]
Here, the inverter and the load 64 drive the load by converting the DC voltage smoothed by the smoothing capacitor 63 into a three-phase AC power source by pulse modulation and providing it to the motor M.
In the initial stage of power application, the control unit 65 turns on or off the switching element Q1, adjusts the current and voltage flowing through the smoothing capacitor 63, and performs PAM driving.
[0032]
If the control unit 65 does not perform PAM driving, the waveforms of the input current and the input voltage represent waveforms as shown in FIG. 4A, and if PAM driving is performed, the waveforms of the input current and the input voltage are This is as shown in FIG.
That is, when the PAM drive is not performed, the phase of the input current and the input voltage is different from each other, but the phase of the input current and the input voltage is the same during the PAM drive.
[0033]
Here, the input voltage sensing unit 66 and the input current sensing unit 67 sense the voltage and current input from the inverter and the load side through the rectifying unit 61 and provide them to the control unit 65.
As described above, when a predetermined time elapses after the inverter and the load are operated by PAM driving from the beginning, the control unit 65 determines the input voltage and the input current provided by the input voltage sensing unit 66 and the input current sensing unit 67. accept.
[0034]
At the same time, as shown in FIG. 4A, when the input voltage is sensed and the phases of the current and the voltage do not match, the inverter and the load 64 are not driven. This is because if the inverter and the load 64 are driven in a state where the input voltage and the input current are not in phase, the efficiency is reduced, and noise interference occurs in the vicinity of the inverter and the load 64.
However, when the predetermined time has elapsed, as shown in FIG. 4B, the phases of the input voltage and the input current are matched. At this time, the control unit 65 sends out a drive signal for driving the inverter and the load 64. Inverter / load 64 is driven.
[0035]
The drive signal of the control unit 65 here is a spherical wave.
Thus, when the input voltage and the input current are in phase, driving the inverter and the load 64 is more efficient and economical, and noise can be reduced.
Further, when the input power supply voltage is a low voltage, driving only the inverter / load 64 without driving with the PAM is advantageous for the inverter and the load 64 that prioritize efficiency.
[0036]
The process described above will be described with reference to FIG.
According to FIG. 5, the power factor correction device of the inverter system is initially driven by PAM (S101).
As described above, after the PAM drive is initially performed, when a certain time elapses, the waveforms of the input current and the input voltage are sensed (S102).
[0037]
Thereafter, the phase of the waveform of the sensed input current and the input voltage is compared (S103), and if it is in phase (S104), the inverter and the load 64 are driven (S105), and if not in phase (S104), the inverter and load 64 are It can be driven efficiently so as not to drive (S106).
[0038]
【The invention's effect】
As described above, in the power factor correction apparatus for an inverter system according to the present invention, the PAM function is selectively operated, and is generated around the initial stage of power application, the initial stage of driving the inverter motor, and the driving period of the PAM switching element. There is an effect of solving the interference problem and driving the PAM function more efficiently and economically.
[0039]
In addition, when driving the inverter and the load, the present invention senses the waveforms of the input voltage and the input current when a predetermined time elapses after the PAM is driven in the initial stage. By not driving the inverter and the load when they are not in phase, more efficient and economical driving can be performed, noise can be reduced, and the current state of interference can be prevented.
[0040]
Further, when the power supply voltage is low, there is an effect that it is possible to control only the inverter and the load giving priority to efficiency.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a first embodiment of an inverter power factor correction apparatus according to the present invention;
FIG. 2 is a block diagram showing a second embodiment of an inverter power factor correction apparatus according to the present invention;
FIG. 3 is a block diagram showing an inverter system according to the present invention.
FIG. 4 is a waveform diagram of an input voltage and an input current when PAM driving is not performed in the inverter system according to the present invention, and a waveform diagram of an input voltage and an input current when PAM driving is performed.
FIG. 5 is a flowchart showing an operation process of the inverter system according to the present invention.
FIG. 6 is a block circuit diagram showing a conventional inverter system.
7 is a waveform diagram of input / output of each unit in FIG. 6;
FIG. 8 is a circuit diagram showing a power factor correction device of a conventional inverter system.
9 is a detailed view of FIG.
10 is a detailed view showing an analog power factor improvement unit of FIG. 9;
11 is a waveform diagram of input / output of each unit in FIG. 9;
[Explanation of symbols]
61 ... rectifier 62 ... choke coil 63 ... smoothing capacitor 64 ... inverter and load 65 ... controller 66 ... input current detector 67 ... input voltage detector 100 ... rectifier 110 ... inverter 120 ... motor 200 ... controller 210 ... Relay drive unit 220 ... Relay

Claims (2)

Including a rectifying section for rectifying a commercial AC power source, a smoothing unit comprising a choke coil and a smoothing capacitor for smoothing an output voltage of the rectifier unit and an inverter unit for outputting a variable frequency and variable voltage in accordance with the output from the smooth portion In the inverter system,
An input voltage sensing unit for sensing an input voltage of the commercial AC power source input from the commercial AC power source to the rectifying unit ;
An input current sensing unit that senses an input current of the commercial AC power source that is input from the commercial AC power source to the rectifying unit ;
A switching element connected in parallel to the preceding stage of the smoothing capacitor;
A control unit for turning on or off the switching element,
The control unit turns on or off the switching element in the initial stage of power supply application, performs pulse amplitude modulation driving by adjusting a current to the smoothing capacitor and a voltage supplied to the inverter unit, and the sensed A drive device for an inverter system, which compares waveforms of an input voltage and an input current and sends a drive signal only when they are in phase to drive an inverter and a load. A rectifying unit for rectifying a commercial AC power supply; a smoothing unit including a choke coil and a smoothing capacitor for smoothing an output voltage of the rectifying unit; and an inverter unit for outputting a variable frequency and a variable voltage according to an output from the smoothing unit. In the driving method of the inverter system,
A pulse amplitude modulation drive is performed by adjusting the current to the smoothing capacitor and the voltage supplied to the inverter unit by turning on or off the switching element connected in parallel to the preceding stage of the smoothing capacitor in the initial stage of power application . One step,
A second step of sensing an input voltage and an input current of the commercial AC power source input from the commercial AC power source to the rectifying unit after performing pulse amplitude modulation driving in the first step for a predetermined time;
A third step of comparing waveforms of the input voltage and the input current sensed in the second step;
If the input voltage and the input current compared in the third stage are in phase, the drive signal is sent to drive the inverter and the load. If not , the drive signal is stopped and the inverter and the load are driven. fourth stage and a driving method of an inverter system which is characterized in that the not allowed.

Images