JP7014597B2 - Inverter device, booster circuit control method and program - Google Patents

Description

The present invention relates to an inverter device, a booster circuit control method and a program.

In relation to the power supply to the motor, the motor control device described in Patent Document 1 includes full-wave rectification and voltage doubler rectification that generates twice the voltage obtained by full-wave rectification and supplies the voltage to the motor. To supply voltage to the motor. Further, the motor control device described in Patent Document 1 performs field weakening control when the motor voltage exceeds a predetermined value, and switches between full-wave rectification and voltage doubler rectification based on the current value of field weakening control. On the other hand, the motor control device described in Patent Document 1 does not perform field weakening control in a region where the operation becomes unstable, and is full-wave based on a modulation factor indicating the relationship between the voltage required for the motor input and the voltage of the smoothing capacitor. Switch between rectification and voltage doubler rectification.

Japanese Unexamined Patent Publication No. 2011-234466

In the motor control device described in Patent Document 1, in order to avoid abnormal stop such as step-out, full-wave rectification and voltage doubler rectification are switched in the region where the operation becomes unstable without performing field weakening control. , Avoid switching during field weakening control.
On the other hand, it is preferable that the possibility of step-out at the time of switching between full-wave rectification and voltage doubler rectification can be reduced even when the field weakening control is not performed.

The present invention provides an inverter device, a booster circuit control method, and a program that can reduce the possibility of step-out during switching between full-wave rectification and voltage doubler rectification even when field weakening control is not performed.

According to the first aspect of the present invention, the inverter device has a 1x DC voltage and a 2x DC voltage corresponding to twice the 1x DC voltage with respect to the inverter circuit that supplies power to the motor. A booster circuit that supplies a DC voltage of any of the intermediate voltage, which is an intermediate voltage between the 1x DC voltage and the 2x DC voltage, and the booster circuit obtains the 1x DC voltage. A booster circuit control unit that controls the booster circuit so as to supply the double-voltage DC voltage after supplying the intermediate voltage from the state of supplying the inverter circuit is provided , and the booster circuit supplies a voltage. From the positive side of the output of the rectifying circuit to the positive input terminal of the DC side of the inverter circuit at the position where the positive side of the output of the original rectifying circuit and the positive input terminal on the DC side of the inverter circuit are connected. The negative side of the direct current side of the inverter circuit is located at the position where the main diode on the positive side provided in the direction of flowing current and the negative side of the output of the rectifying circuit and the negative input terminal on the direct current side of the inverter circuit are connected. The negative electrode side main diode provided in the direction of flowing current from the input terminal to the negative side of the output of the rectifying circuit, between the positive electrode side main diode and the positive input terminal on the DC side of the inverter circuit, and the negative electrode. At the position where the side main diode and the negative input terminal on the DC side of the inverter circuit are connected, the positive electrode side capacitor is located between the positive side main diode and the positive input terminal on the DC side of the inverter circuit. The positive and negative side capacitors are connected in series with the negative side capacitor located between the negative side main diode and the DC side negative input terminal of the inverter circuit, and the rectification. It is provided at a position connecting between the positive side of the output of the circuit and the main diode on the positive current side, and between the capacitor on the positive current side and the capacitor on the negative current side. The positive current side switching element forming a circuit connecting both ends of the negative current side capacitor, between the negative side of the output of the rectifying circuit and the negative current side main diode, the positive current side capacitor and the negative current side capacitor. The booster circuit is provided with a negative-current switching element that is provided at a position connecting the space between the two and forms a circuit that connects both ends of the rectifying circuit and both ends of the positive-current side capacitor when the rectifying circuit is turned on. The control unit turns off both the positive-side switching element and the negative-side switching element, so that the booster voltage is supplied to the inverter circuit. By controlling the path, repeatedly turning on / off one of the positive-side switching element and the negative-side switching element, and turning off the other switching element, the booster circuit is in the middle. By controlling to supply a voltage, switching on / off of these switching elements so that one of the positive side switching element and the negative side switching element is turned on and the other switching element is turned off. By repeating the above steps, the booster circuit is controlled to supply the double voltage DC voltage.

The booster circuit control unit is a booster circuit so that the booster circuit supplies the double-voltage DC voltage to the inverter circuit, supplies the intermediate voltage, and then supplies the double-voltage DC voltage. May be controlled.

According to the second aspect of the present invention, the booster circuit control method connects the positive side of the output of the rectifying circuit, which is the voltage supply source, and the positive input terminal of the DC side of the inverter circuit that supplies power to the motor. The positive side main diode provided in the direction of flowing current from the positive side of the output of the rectifying circuit to the positive input terminal on the DC side of the inverter circuit, the negative side of the output of the rectifying circuit, and the inverter. A negative-side main diode provided at a position connecting the negative input terminal on the DC side of the circuit so that a current flows from the negative input terminal on the DC side of the inverter circuit to the negative side of the output of the rectifying circuit. At a position connecting the positive side main diode and the DC side positive input terminal of the inverter circuit and the negative side main diode and the DC side negative input terminal of the inverter circuit. The positive side capacitor is located between the positive side main diode and the DC side positive input terminal of the inverter circuit, and the negative side capacitor is the negative side main diode and the DC side negative input terminal of the inverter circuit. The positive and negative side capacitors connected in series in an arrangement located between the positive and negative currents, between the positive and positive side of the output of the rectifier circuit, and between the positive and negative side capacitors. A positive current side switching element, which is provided at a position connecting between the capacitor and a positive current side switching element that forms a circuit connecting both ends of the rectifying circuit and both ends of the negative current side capacitor by turning on itself, and the rectifying circuit. It is provided at a position connecting between the negative side of the output and the main diode on the negative side, and between the capacitor on the positive side and the capacitor on the negative side. It is provided with a negative-side switching element that forms a circuit that connects both ends of the positive-side capacitor, and has a double-voltage DC voltage and a double-pressure equivalent to twice the single-voltage DC voltage with respect to the inverter circuit . The positive side switching element and the negative side with respect to the booster circuit that supplies the DC voltage of any of the DC voltage and the intermediate voltage that is the intermediate voltage between the 1x DC voltage and the 2x DC voltage. By turning off both of the switching elements, the booster circuit is controlled so that the booster DC voltage is supplied to the inverter circuit, and switching of either the positive side switching element or the negative side switching element is performed. The booster circuit supplies the intermediate voltage by repeatedly switching the element on / off and turning off the other switching element. By repeating on / off switching of these switching elements so that one of the positive side switching element and the negative side switching element is turned on and the other switching element is turned off. By controlling the booster circuit to supply the double-voltage DC voltage, the booster circuit supplies the intermediate voltage from the state in which the booster circuit supplies the double-voltage DC voltage to the inverter circuit, and then the intermediate voltage is supplied. It involves controlling the booster circuit to supply a double voltage DC voltage.

According to the third aspect of the present invention, the program is located at a position connecting the positive side of the output of the rectifying circuit, which is the voltage supply source, and the positive input terminal of the DC side of the inverter circuit that supplies power to the motor. The positive side main diode provided in the direction of flowing current from the positive side of the output of the rectifying circuit to the positive input terminal on the DC side of the inverter circuit, the negative side of the output of the rectifying circuit, and the direct current of the inverter circuit. The negative side main diode provided at the position where the negative input terminal on the side is connected so that a current flows from the negative input terminal on the DC side of the inverter circuit to the negative side of the output of the rectifying circuit, and the positive side. A positive capacitor at a position connecting the side main diode and the positive input terminal on the DC side of the inverter circuit and between the main diode on the negative side and the negative input terminal on the DC side of the inverter circuit. Is located between the positive side main diode and the DC side positive input terminal of the inverter circuit, and the negative side capacitor is located between the negative side main diode and the DC side negative input terminal of the inverter circuit. A positive current side capacitor and a negative current side capacitor connected in series in an arrangement located on the side, between the positive side and the positive current side main diode of the output of the rectifying circuit, and the positive current side capacitor and the negative current side capacitor. A positive current side switching element that is provided at a position connecting between the direct currents and forms a circuit that connects both ends of the rectifying circuit and both ends of the negative current side capacitor by turning on itself, and a negative output of the rectifying circuit. It is provided at a position connecting between the side and the negative current side main diode and between the positive current side capacitor and the negative current side capacitor, and when it is turned on by itself, both ends of the rectifying circuit and the positive current side capacitor are provided. A negative-voltage side switching element that forms a circuit that connects both ends of the circuit is provided, and the inverter circuit is provided with a single-voltage DC voltage and a double-voltage DC voltage that is twice the single-voltage DC voltage. , The positive side switching element and the negative side to the computer that controls the booster circuit that supplies the DC voltage of any of the intermediate voltage that is the intermediate voltage between the 1x DC voltage and the 2x DC voltage. By turning off both of the switching elements, the booster circuit is controlled so that the booster DC voltage is supplied to the inverter circuit, and switching of either the positive side switching element or the negative side switching element is performed. By repeatedly switching the element on / off and turning off the other switching element, the booster circuit activates the intermediate power. By controlling to supply voltage, switching on / off of these switching elements so that one of the positive-current side switching element and the negative-position side switching element is turned on and the other switching element is turned off. By controlling the booster circuit to supply the double-voltage DC voltage by repeating the above steps, the booster circuit supplies the intermediate voltage from the state of supplying the single-voltage DC voltage to the inverter circuit. After that, it is a program for controlling the booster circuit so as to supply the double voltage DC voltage.

According to the above-mentioned inverter device, booster circuit control method and program, it is possible to reduce the possibility of step-out when switching between full-wave rectification and voltage doubler rectification even when field weakening control is not performed.

It is a figure which shows the circuit structure of the inverter device which concerns on this embodiment. It is a schematic block diagram which shows the functional structure of the step-up circuit control part which concerns on the same embodiment. It is a figure which shows the example of the on / off of a positive electrode side switching element and a negative electrode side switching element in the 1x pressure mode in the same embodiment. It is a figure which shows the example of on / off of a positive electrode side switching element and a negative electrode side switching element in the intermediate voltage mode in the same embodiment. It is a figure which shows the example of the on / off of a positive electrode side switching element and a negative electrode side switching element in the double pressure mode in the same embodiment. It is a figure which shows the example of the value of the DC voltage at the time of switching from a 1x voltage mode to an intermediate voltage mode and a 2x voltage mode in the same embodiment. It is a figure which shows the example of the value of the DC voltage at the time of switching from a double voltage mode to an intermediate voltage mode and a single voltage mode in the same embodiment.

Hereinafter, embodiments of the present invention will be described, but the following embodiments do not limit the invention within the scope of the claims. Also, not all combinations of features described in the embodiments are essential to the means of solving the invention.

(Circuit configuration of inverter device)
FIG. 1 is a diagram showing a circuit configuration of an inverter device according to the present embodiment.
The inverter device 1 is mounted on the outdoor unit of the air conditioner (air conditioner) 90. The inverter device 1 outputs a load driving AC voltage (three-phase AC voltage) according to a separately input rotation speed command to the three-phase AC motor (motor 4) for driving the compressor of the outdoor unit. do. The inverter device 1 rotationally drives the load three-phase AC motor (motor 4) at a desired rotation speed based on the load driving AC voltage.
The inverter device 1 converts the three-phase AC voltage supplied from the three-phase AC power supply 3, which is a commercial power source, into the load driving AC voltage and outputs the voltage. Here, the three-phase AC power supply 3 is, for example, an AC voltage having an AC of 200 V (effective value of 200 V) and a frequency of 50 Hz (or 60 Hz), and is composed of an R phase, an S phase, and a T phase whose phases differ by 120 ° from each other. Outputs the phase AC voltage. Hereinafter, the AC voltage of each phase output by the three-phase AC power supply 3 is also described as “R-phase AC voltage”, “S-phase AC voltage”, and “T-phase AC voltage”, respectively.

As shown in FIG. 1, the inverter device 1 includes a three-phase voltage doubler rectifier circuit 1A, an inverter circuit 20, an inverter circuit control unit 21, and a rotation speed detection unit 13.

The three-phase voltage doubler rectifier circuit 1A rectifies the three-phase AC voltage supplied from the three-phase AC power supply 3 and outputs "DC voltage Vdc". The DC voltage Vdc, which is the output voltage of the three-phase voltage doubler rectifier circuit 1A, is output between the positive electrode side output terminal Qa and the negative electrode side output terminal Qb shown in FIG.
As will be described later, the three-phase voltage doubler rectifier circuit 1A according to the present embodiment has a function as a voltage doubler rectifier circuit that outputs a double voltage of the maximum value of the input three-phase AC voltage.

The inverter circuit 20 converts the DC voltage Vdc output from the three-phase voltage doubler rectifier circuit 1A into a load driving AC voltage for rotationally driving the motor 4. The inverter circuit 20 has three pairs of two switching elements connected in series between the positive electrode side output terminal Qa and the negative electrode side output terminal Qb. Here, the switching element is, for example, a power transistor such as an insulated gate bipolar transistor (IGBT). Each pair of the switching elements connected in series corresponds to each of the three phases for rotationally driving the three-phase AC motor (motor 4).
The inverter circuit 20 further includes a motor current detection unit 22.
The motor current detection unit 22 detects the current (motor current) returning to the three-phase voltage doubler rectifier circuit 1A. The motor current detection unit 22 outputs the detection result of the detected motor current as a detection signal to the inverter circuit control unit 21.

The inverter circuit control unit 21 is a control IC (so-called microcomputer or the like) that controls on / off of each switching element constituting the inverter circuit 20.
A rotation speed command is input to the inverter circuit control unit 21 from the host device. The inverter circuit control unit 21 receives a motor current detection signal from the motor current detection unit 22.
The inverter circuit control unit 21 drives the inverter circuit 20 so that the rotation speed of the motor 4 becomes the rotation speed indicated by the rotation speed command while monitoring the motor current. Here, the inverter circuit control unit 21 controls the inverter circuit 20 based on the generally well-known PWM (Pulse Width Modulation) control.

(Construction of three-phase voltage doubler rectifier circuit)
The circuit configuration of the three-phase voltage doubler rectifier circuit 1A will be described in detail.
As shown in FIG. 1, the three-phase voltage doubler rectifier circuit 1A includes a rectifier circuit 10, a booster circuit 11, a booster circuit control unit 12, and a reactor L.

The rectifier circuit 10 rectifies the three-phase AC voltage supplied from the three-phase AC power supply 3 and outputs the rectified voltage Vac.
The booster circuit 11 can output a voltage that is twice the maximum value of the three-phase AC voltage input from the three-phase AC power supply 3 as a DC voltage Vdc under the control of the booster circuit control unit 12.
The booster circuit control unit 12 is a control IC that controls the booster circuit 11. The specific functional configuration of the booster circuit control unit 12 will be described later.
The rectifier circuit 10 and the booster circuit 11 are connected to each other on the positive electrode side by a positive electrode output line α via the reactor L. The rectifier circuit 10 and the booster circuit 11 are connected to each other on the negative electrode side by a negative electrode output line β.

The reactor L smoothes the current flowing through the positive electrode output line α.
In the following description, the positive electrode output line α is a line in which the first positive electrode output line α1 and the second positive electrode output line α2 are connected in series via the reactor L.
Therefore, the rectifier circuit 10 outputs the rectified voltage Vac between the first positive electrode output line α1 and the negative electrode output line β.

(Rectifier circuit configuration)
The rectifier circuit 10 will be described in detail.
The rectifying circuit 10 inputs the three-phase AC voltage (R-phase AC voltage, S-phase AC voltage, and T-phase AC voltage) supplied from the three-phase AC power supply 3 to three input terminals (R-phase input) corresponding to each phase. Input from each of the terminal QR, S-phase input terminal QS, and T-phase input terminal QT) to rectify.

Each of the R-phase AC voltage, the S-phase AC voltage, and the T-phase AC voltage vibrates with a period Tc while being out of phase with each other by 120 °.
The rectifier circuit 10 includes six rectifier diodes (positive side R-phase rectifier diode 10Ra, negative-side R-phase rectifier diode 10Rb, positive-side S-phase rectifier diode 10Sa, negative-side S-phase rectifier diode 10Sb, positive-side T-phase rectifier diode 10Ta, and It is composed of a negative side T-phase rectifying diode 10Tb).

The positive-side R-phase rectifier diode 10Ra and the negative-side R-phase rectifier diode 10Rb of the rectifier circuit 10 rectify the R-phase AC voltage input from the three-phase AC power supply 3 through the R-phase input terminal QR. Specifically, the positive electrode side R phase rectifier diode 10Ra is forwardly connected from the R phase input terminal QR to the first positive electrode output line α1. Further, the negative electrode side R phase rectifying diode 10Rb is forwardly connected from the negative electrode output line β to the R phase input terminal QR.

The positive side S-phase rectifier diode 10Sa and the negative side S-phase rectifier diode 10Sb of the rectifier circuit 10 rectify the S-phase AC voltage input from the three-phase AC power supply 3 through the S-phase input terminal QS. Specifically, the positive electrode side S-phase rectifying diode 10Sa is forwardly connected from the S-phase input terminal QS to the first positive electrode output line α1. Further, the negative electrode side S-phase rectifying diode 10Sb is forwardly connected from the negative electrode output line β to the S-phase input terminal QS.

The positive side T-phase rectifier diode 10Ta and the negative side T-phase rectifier diode 10Tb of the rectifier circuit 10 rectify the T-phase AC voltage input from the three-phase AC power supply 3 through the T-phase input terminal QT. Specifically, the positive electrode side T-phase rectifying diode 10Ta is forwardly connected from the T-phase input terminal QT to the first positive electrode output line α1. Further, the negative electrode side T-phase rectifying diode 10Tb is forwardly connected from the negative electrode output line β to the T-phase input terminal QT.

(Boost circuit)
The booster circuit 11 will be described in detail.
The booster circuit 11 can output a voltage twice the maximum value of the three-phase AC voltage input from the three-phase AC power supply 3 as the DC voltage Vdc which is the output voltage of the three-phase voltage doubler rectifier circuit 1A. ..
Here, in the following description, the DC voltage Vdc corresponding to the amplitude of the three-phase AC voltage is described as "single voltage DC voltage Vdc1", and the DC voltage Vdc equivalent to twice the amplitude of the three-phase AC voltage is described as "1x voltage DC voltage Vdc1". It is distinguished by describing it as "double voltage DC voltage Vdc2" (Vdc1 = 1/2 · Vdc2). For example, when the three-phase AC power supply 3 outputs an AC voltage of AC200V, the single-voltage DC voltage Vdc1 becomes 200√2V, and the double-voltage DC voltage Vdc2 becomes 400√2V. Further, the voltage between the single voltage DC voltage Vdc1 and the double voltage DC voltage Vdc2 is described as "intermediate voltage Vdc3". Vdc1 <Vdc3 <Vdc2.
The 1x DC voltage Vdc1 corresponds to an example of a reference voltage which is a voltage before being boosted.

The booster circuit 11 comprises a positive electrode side main diode Da, a negative electrode side main diode Db, a positive electrode side switching element 11a, a negative electrode side switching element 11b, and two capacitors (positive electrode side capacitor Ca and negative electrode side capacitor Cb). Be prepared.

The two capacitors (positive electrode side capacitor Ca and negative electrode side capacitor Cb) are connected in series between the outputs on the output side of the booster circuit 11.
Specifically, the positive electrode side capacitor Ca is connected between the cathode of the positive electrode side main diode Da and the connection point N. The negative electrode side capacitor Cb is connected between the anode of the negative electrode side main diode Db and the connection point N.
The positive electrode side capacitor Ca and the negative electrode side capacitor Cb have the same capacitance value. Therefore, the connection point N is an intermediate potential point of the potential difference between the positive electrode output line α and the negative electrode output line β.

The positive electrode side main diode Da is connected in the forward direction from the positive electrode output line α of the rectifier circuit 10 to the positive electrode side capacitor Ca. Specifically, the anode of the positive electrode side main diode Da is connected to the second positive electrode output line α2, and the cathode of the positive electrode side main diode Da is connected to the positive electrode side capacitor Ca.
The negative electrode side main diode Db is connected in the forward direction from the negative electrode side capacitor Cb to the negative electrode output line β of the rectifier circuit 10. Specifically, the anode of the negative electrode side main diode Db is connected to the negative electrode side capacitor Cb, and the cathode of the negative electrode side main diode Db is connected to the negative electrode output line β.

The positive electrode side switching element 11a and the negative electrode side switching element 11b are power transistors, respectively.
The positive electrode side switching element 11a is connected between the positive electrode output line α (second positive electrode output line α2) and the connection point N. The negative electrode side switching element 11b is connected between the negative electrode output line β and the connection point N.
The positive electrode side switching element 11a and the negative electrode side switching element 11b are on / off controlled by a switching control signal output from the booster circuit control unit 12 described later.

In the case of this embodiment, the positive electrode side switching element 11a and the negative electrode side switching element 11b are IGBTs, respectively.
In this case, the collector of the positive electrode side switching element 11a is connected to the second positive electrode output line α2, and the emitter of the positive electrode side switching element 11a is connected to the connection point N. Further, the emitter of the negative electrode side switching element 11b is connected to the negative electrode output line β, and the collector of the negative electrode side switching element 11b is connected to the connection point N.
By applying a switching control signal from the booster circuit control unit 12 described later to the gate of the positive electrode side switching element 11a, the positive electrode side switching element 11a is controlled on / off.
Similarly, the negative electrode side switching element 11b is on / off controlled by applying a switching control signal from the booster circuit control unit 12 to the gate of the negative electrode side switching element 11b.

(Boost circuit control unit)
The booster circuit control unit 12 will be described in detail.
FIG. 2 is a schematic block diagram showing a functional configuration of the booster circuit control unit 12.
As shown in FIG. 2, the booster circuit control unit 12 includes a mode determination unit 12d and a switching element control unit 12g.
The mode determination unit 12d determines the control mode of the booster circuit 11 to be one of a single voltage mode, an intermediate voltage mode, and a double voltage mode.
The switching element control unit 12g controls on / off of the positive electrode side switching element 11a and the negative electrode side switching element 11b according to the mode determined by the mode determination unit 12d.

Next, the operation of the inverter device 1 will be described with reference to FIGS. 3 to 7.
FIG. 3 is a diagram showing an example of turning on / off the positive electrode side switching element 11a and the negative electrode side switching element 11b in the single pressure mode. The horizontal axis in FIG. 3 indicates the time.
In the single pressure mode, the switching element control unit 12g leaves both the positive electrode side switching element 11a and the negative electrode side switching element 11b in the off state.
In the single pressure mode, when the rotation speed of the motor 4 detected by the rotation speed detection unit 13 becomes larger than a predetermined threshold value, the mode determination unit 12d switches the control mode of the booster circuit 11 to the intermediate voltage mode.

FIG. 4 is a diagram showing an example of turning on / off the positive electrode side switching element 11a and the negative electrode side switching element 11b in the intermediate voltage mode. The horizontal axis in FIG. 4 indicates the time.
In the intermediate voltage mode, the switching element control unit 12g repeatedly switches the positive electrode side switching element 11a on and off, and leaves the negative electrode side switching element 11b in the off state. Alternatively, the switching element control unit 12g may leave the positive electrode side switching element 11a in the off state and repeat on / off switching of the negative electrode side switching element 11b.
When a predetermined time has elapsed after switching from the single voltage mode to the intermediate voltage mode, the switching element control unit 12g switches from the intermediate voltage mode to the double voltage mode.

FIG. 5 is a diagram showing an example of turning on / off the positive electrode side switching element 11a and the negative electrode side switching element 11b in the double pressure mode. The horizontal axis in FIG. 5 indicates the time.
In the double pressure mode, the switching element control unit 12g alternately switches on / off so that either one of the positive electrode side switching element 11a and the negative electrode side switching element 11b is turned on and the other is turned off. The switching element control unit 12g repeats this on / off switching.

In the double pressure mode, when the rotation speed of the motor 4 detected by the rotation speed detection unit 13 becomes equal to or less than a predetermined threshold value, the mode determination unit 12d switches the control mode of the booster circuit 11 to the intermediate voltage mode. When a predetermined time has elapsed after switching from the double voltage mode to the intermediate voltage mode, the switching element control unit 12g switches from the intermediate voltage mode to the single voltage mode.

The inverter circuit control unit 21 switches the control for the inverter circuit 20 according to the switching of the single voltage mode, the intermediate voltage mode, and the double voltage mode. For example, the inverter circuit control unit 21 switches the calculation standard of the pulse width in the PWM control. In the double pressure mode, the standard for calculating the pulse width is half that in the single pressure mode is used, and in the intermediate voltage mode, the pulse width is calculated in the middle between the case of the single pressure mode and the case of the double pressure mode. Use criteria.

In this way, the inverter circuit control unit 21 switches the pulse width in the PWM control according to the mode, so that the booster circuit control unit 12 can switch the mode so that the pulse width becomes relatively wide. In this respect, the efficiency of power supply to the motor 4 can be relatively high.
Further, the inverter circuit control unit 21 can control the inverter circuit 20 in response to mode switching by a relatively simple process of switching the pulse width in PWM control in three stages.

FIG. 6 is a diagram showing an example of the value of the DC voltage Vdc when switching from the single voltage mode to the intermediate voltage mode and the double voltage mode. The horizontal axis of the graph of FIG. 6 indicates the time, and the vertical axis indicates the DC voltage Vdc. In the example of FIG. 6, the mode determination unit 12d switches the control mode of the booster circuit 11 in the order of the single voltage mode, the intermediate voltage mode, and the double voltage mode.
As described above, when the rotation speed of the motor 4 detected by the rotation speed detection unit 13 becomes larger than a predetermined threshold value in the single pressure mode, the mode determination unit 12d switches the control mode of the booster circuit 11 to the intermediate voltage mode. .. When a predetermined time has elapsed after switching from the single voltage mode to the intermediate voltage mode, the switching element control unit 12g switches from the intermediate voltage mode to the double voltage mode.

In the single voltage mode, both the positive electrode side switching element 11a and the negative electrode side switching element 11b are turned off, and the DC voltage Vdc becomes the single voltage DC voltage Vdc1 corresponding to the amplitude of the three-phase AC voltage.
In the intermediate voltage mode, the switching element control unit 12g switches on / off the positive electrode side switching element 11a. When the positive electrode side switching element 11a is turned on, a circuit connecting both ends of the rectifying circuit 10 and both ends of the negative electrode side capacitor Cb is formed, and the voltage of the negative electrode side capacitor Cb is a voltage corresponding to the single voltage DC voltage Vdc1. The negative electrode side capacitor Cb is charged with electricity so as to be. As a result, the DC voltage Vdc becomes an intermediate voltage Vdc3 higher than the single voltage DC voltage Vdc1.

In the double pressure mode, the switching element control unit 12g alternately switches on / off so that either one of the positive electrode side switching element 11a and the negative electrode side switching element 11b is turned on and the other is turned off.
When the positive electrode side switching element 11a is turned on, a circuit connecting both ends of the rectifying circuit 10 and both ends of the negative electrode side capacitor Cb is formed, and the voltage of the negative electrode side capacitor Cb is a voltage corresponding to the single voltage DC voltage Vdc1. The negative electrode side capacitor Cb is charged with electricity so as to be. Further, when the negative electrode side switching element 11b is turned on, a circuit connecting both ends of the rectifying circuit 10 and both ends of the positive electrode side capacitor Ca is formed, and the voltage of the positive electrode side capacitor Ca corresponds to the single voltage DC voltage Vdc1. Storage is performed in the positive electrode side capacitor Ca so that the voltage becomes the same.
As a result, the DC voltage Vdc becomes a double voltage DC voltage Vdc2 which is higher than the intermediate voltage Vdc3 and which is twice the single voltage DC voltage Vdc1.

Compared to the case where the DC voltage Vdc is switched from the 1x DC voltage Vdc1 to the intermediate voltage Vdc3 and then switched to the 2x DC voltage Vdc2 to directly switch from the 1x DC voltage Vdc1 to the 2x DC voltage Vdc2. Therefore, sudden changes in the voltage supplied to the motor 4 can be suppressed. This makes it possible to reduce the possibility that the motor 4 will step out.

FIG. 7 is a diagram showing an example of the value of the DC voltage Vdc when switching from the double voltage mode to the intermediate voltage mode and the single voltage mode. The horizontal axis of the graph of FIG. 7 shows the time, and the vertical axis shows the DC voltage Vdc. In the example of FIG. 7, the mode determination unit 12d switches the control mode of the booster circuit 11 in the order of double voltage mode, intermediate voltage mode, and single voltage mode.
As described above, when the rotation speed of the motor 4 detected by the rotation speed detection unit 13 becomes equal to or less than a predetermined threshold value in the double pressure mode, the mode determination unit 12d switches the control mode of the booster circuit 11 to the intermediate voltage mode. .. When a predetermined time has elapsed after switching from the double voltage mode to the intermediate voltage mode, the switching element control unit 12g switches from the intermediate voltage mode to the single voltage mode.
Compared to the case where the DC voltage Vdc is switched from the double voltage DC voltage Vdc2 to the intermediate voltage Vdc3 and then switched to the single voltage DC voltage Vdc1 to directly switch from the double voltage DC voltage Vdc2 to the single voltage DC voltage Vdc1. Therefore, sudden changes in the voltage supplied to the motor 4 can be suppressed. This makes it possible to reduce the possibility that the motor 4 will step out.

As described above, the booster circuit 11 has a single voltage DC voltage Vdc1 and a double voltage DC voltage Vdc2 equivalent to twice the single voltage DC voltage Vdc1 with respect to the inverter circuit 20 that supplies power to the motor 4. , The DC voltage of any one of the intermediate voltage Vdc3, which is an intermediate voltage between the single voltage DC voltage Vdc1 and the double voltage DC voltage Vdc2, is supplied. The booster circuit control unit 12 supplies the booster circuit 11 so that the booster circuit 11 supplies the intermediate voltage Vdc3 and then the double voltage DC voltage Vdc2 from the state where the booster circuit 11 supplies the booster DC voltage Vdc1 to the inverter circuit 20. To control.
Compared to the case where the DC voltage Vdc is switched from the 1x DC voltage Vdc1 to the intermediate voltage Vdc3 and then switched to the 2x DC voltage Vdc2 to directly switch from the 1x DC voltage Vdc1 to the 2x DC voltage Vdc2. Therefore, sudden changes in the voltage supplied to the motor 4 can be suppressed. This makes it possible to reduce the possibility that the motor 4 will step out. In particular, the possibility of step-out of the motor 4 can be reduced regardless of the presence or absence of field weakening control.

Further, the booster circuit control unit 12 boosts the booster circuit 11 so that the booster circuit 11 supplies the double voltage DC voltage Vdc2 to the inverter circuit 20, then supplies the intermediate voltage Vdc3 and then supplies the double voltage DC voltage Vdc1. It controls the circuit 11.
Compared to the case where the DC voltage Vdc is switched from the double voltage DC voltage Vdc2 to the intermediate voltage Vdc3 and then switched to the single voltage DC voltage Vdc1 to directly switch from the double voltage DC voltage Vdc2 to the single voltage DC voltage Vdc1. Therefore, sudden changes in the voltage supplied to the motor 4 can be suppressed. This makes it possible to reduce the possibility that the motor 4 will step out. In particular, the possibility of step-out of the motor 4 can be reduced regardless of the presence or absence of field weakening control.

Further, the positive electrode side capacitor Ca and the negative electrode side capacitor Cb are connected in series with the inverter circuit 20. The positive electrode side switching element 11a forms a circuit that connects both ends of the rectifier circuit 10 which is a voltage supply source and both ends of the negative electrode side capacitor Cb when the positive electrode side switching element 11a is turned on. The negative electrode side switching element 11b forms a circuit that connects both ends of the rectifier circuit 10 and both ends of the positive electrode side capacitor Ca by turning on itself. The booster circuit control unit 12 repeatedly switches on / off of one of the positive electrode side switching element 11a and the negative electrode side switching element 11b, and turns off the other switching element, whereby the booster circuit 11 Controls to supply an intermediate voltage. Further, the booster circuit control unit 12 turns on / off these switching elements so that one of the positive side switching element 11a and the negative side switching element 11b is switched on and the other switching element is turned off. By repeating the switching, the booster circuit 11 is controlled to supply the double voltage DC voltage.

As a result, the booster circuit 11 uses an element for supplying a double-voltage DC voltage (particularly, a positive electrode side switching element 11a, a negative electrode side switching element 11b, a positive electrode side capacitor Ca, and a negative electrode side capacitor Cb) in the middle. A voltage can be supplied. The booster circuit 11 does not need to further include an element to supply the intermediate voltage, and in this respect, the booster circuit 11 can be avoided from being complicated.
Further, the booster circuit control unit 12 is relatively simple in that the switching element of either the positive electrode side switching element 11a or the negative electrode side switching element 11b is repeatedly turned on / off and the other switching element is turned off. The booster circuit 11 can be controlled to supply an intermediate voltage.

A program for realizing all or part of the functions of the booster circuit control unit 12 is recorded on a computer-readable recording medium, and the program recorded on the recording medium is read by the computer system and executed. May be processed for each part. The term "computer system" as used herein includes hardware such as an OS and peripheral devices.
Further, the "computer system" includes the homepage providing environment (or display environment) if the WWW system is used.
Further, the "computer-readable recording medium" refers to a portable medium such as a flexible disk, a magneto-optical disk, a ROM, or a CD-ROM, and a storage device such as a hard disk built in a computer system. Further, the above-mentioned program may be for realizing a part of the above-mentioned functions, and may be further realized for realizing the above-mentioned functions in combination with a program already recorded in the computer system.

Although the embodiment of the present invention has been described in detail with reference to the drawings, the specific configuration is not limited to this embodiment and includes design changes and the like within a range not deviating from the gist of the present invention.

1 Inverter device 1A Three-phase voltage doubler rectifier circuit 4 Motor 10 Rectifier circuit 11 Booster circuit 11a Positive side switching element 11b Negative side switching element Ca Positive side capacitor Cb Negative side capacitor 12 Booster circuit control unit 12d Mode determination unit 12g Switching element control unit 13 Rotation speed detector 20 Inverter circuit 21 Inverter circuit control unit

Claims (4)

For the inverter circuit that supplies power to the motor, the single-pressure DC voltage, the double-pressure DC voltage corresponding to twice the single-pressure DC voltage, and the single-pressure DC voltage and the double-pressure DC voltage are used. A booster circuit that supplies any DC voltage from the intermediate voltage, which is the intermediate voltage of
A booster circuit control unit that controls the booster circuit so that the booster circuit supplies the double-voltage DC voltage after supplying the intermediate voltage from the state where the booster circuit supplies the booster DC voltage to the inverter circuit. When,
Equipped with
The booster circuit
A positive input on the DC side of the inverter circuit from the positive side of the output of the rectifier circuit at a position connecting the positive side of the output of the rectifier circuit, which is the voltage supply source, and the positive input terminal on the DC side of the inverter circuit. The main diode on the positive side, which is provided in the direction of passing current to the terminals,
A current is applied from the negative input terminal on the DC side of the inverter circuit to the negative side of the output of the rectifier circuit at the position where the negative side of the output of the rectifier circuit and the negative input terminal on the DC side of the inverter circuit are connected. The main diode on the negative side, which is provided in the direction of flow,
A positive electrode is located between the positive electrode side main diode and the positive input terminal on the DC side of the inverter circuit, and between the negative electrode side main diode and the negative input terminal on the DC side of the inverter circuit. The side capacitor is located between the positive side main diode and the DC side positive input terminal of the inverter circuit, and the negative side capacitor is the negative side main diode and the DC side negative input terminal of the inverter circuit. Positive current side capacitors and negative negative side capacitors connected in series in an arrangement located on the intervening side,
The rectifying circuit is provided at a position connecting between the positive side of the output of the rectifying circuit and the main diode on the positive electrode side, and between the capacitor on the positive electrode side and the capacitor on the negative electrode side. A positive electrode side switching element forming a circuit connecting both ends of the negative electrode side capacitor and both ends of the negative electrode side capacitor,
The rectifying circuit is provided at a position connecting between the negative side of the output of the rectifying circuit and the main diode on the negative electrode side, and between the capacitor on the positive electrode side and the capacitor on the negative electrode side. A negative electrode side switching element forming a circuit connecting both ends of the positive electrode side capacitor and both ends of the positive electrode side capacitor,
Equipped with
The booster circuit control unit controls the booster circuit so as to supply the booster DC voltage to the inverter circuit by turning off both the positive side switching element and the negative side switching element. By repeating on / off switching of one of the positive-side switching element and the negative-side switching element and turning off the other switching element, the booster circuit supplies the intermediate voltage. By controlling and repeating on / off switching of these switching elements so that one of the positive side switching element and the negative side switching element is turned on and the other switching element is turned off, the above-mentioned The booster circuit controls to supply the double voltage DC voltage.
Inverter device. The booster circuit control unit is a booster circuit so that the booster circuit supplies the double-voltage DC voltage to the inverter circuit, supplies the intermediate voltage, and then supplies the double-voltage DC voltage. To control,
The inverter device according to claim 1. From the positive side of the output of the rectifier circuit to the position where the positive side of the output of the rectifier circuit, which is the voltage supply source, is connected to the positive input terminal on the DC side of the inverter circuit that supplies power to the motor. The positive side main diode provided in the direction of passing current to the positive input terminal on the DC side,
A current is applied from the negative input terminal on the DC side of the inverter circuit to the negative side of the output of the rectifier circuit at the position where the negative side of the output of the rectifier circuit and the negative input terminal on the DC side of the inverter circuit are connected. The main diode on the negative side, which is provided in the direction of flow,
A positive electrode is located between the positive electrode side main diode and the positive input terminal on the DC side of the inverter circuit, and between the negative electrode side main diode and the negative input terminal on the DC side of the inverter circuit. The side capacitor is located between the positive side main diode and the DC side positive input terminal of the inverter circuit, and the negative side capacitor is the negative side main diode and the DC side negative input terminal of the inverter circuit. Positive current side capacitors and negative negative side capacitors connected in series in an arrangement located on the intervening side,
The rectifying circuit is provided at a position connecting between the positive side of the output of the rectifying circuit and the main diode on the positive electrode side, and between the capacitor on the positive electrode side and the capacitor on the negative electrode side. A positive electrode side switching element forming a circuit connecting both ends of the negative electrode side capacitor and both ends of the negative electrode side capacitor,
The rectifying circuit is provided at a position connecting between the negative side of the output of the rectifying circuit and the main diode on the negative electrode side, and between the capacitor on the positive electrode side and the capacitor on the negative electrode side. A negative electrode side switching element forming a circuit connecting both ends of the positive electrode side capacitor and both ends of the positive electrode side capacitor,
The above-mentioned inverter circuit is provided with a single-pressure DC voltage, a double-pressure DC voltage corresponding to twice the single-pressure DC voltage, and an intermediate between the single-pressure DC voltage and the double-pressure DC voltage. For the booster circuit that supplies the DC voltage of any of the intermediate voltage that is the voltage of
By turning off both the positive side switching element and the negative side switching element, the booster circuit is controlled so that the single voltage DC voltage is supplied to the inverter circuit, and the positive side switching element and the negative side are used. By repeatedly switching on / off of one of the switching elements and turning off the other switching element, the booster circuit is controlled to supply the intermediate voltage, and the positive side switching is performed. By repeating on / off switching of these switching elements so that one of the switch of the element and the switching element on the negative side is turned on and the other switching element is turned off, the booster circuit has the double voltage. By controlling to supply the DC voltage, the booster circuit supplies the intermediate voltage from the state of supplying the single voltage DC voltage to the inverter circuit, and then supplies the double voltage DC voltage. , A booster circuit control method comprising controlling the booster circuit. From the positive side of the output of the rectifier circuit to the position where the positive side of the output of the rectifier circuit, which is the voltage supply source, is connected to the positive input terminal on the DC side of the inverter circuit that supplies power to the motor. The positive side main diode provided in the direction of passing current to the positive input terminal on the DC side,
A current is applied from the negative input terminal on the DC side of the inverter circuit to the negative side of the output of the rectifier circuit at the position where the negative side of the output of the rectifier circuit and the negative input terminal on the DC side of the inverter circuit are connected. The main diode on the negative side, which is provided in the direction of flow,
A positive electrode is located between the positive electrode side main diode and the positive input terminal on the DC side of the inverter circuit, and between the negative electrode side main diode and the negative input terminal on the DC side of the inverter circuit. The side capacitor is located between the positive side main diode and the DC side positive input terminal of the inverter circuit, and the negative side capacitor is the negative side main diode and the DC side negative input terminal of the inverter circuit. Positive current side capacitors and negative negative side capacitors connected in series in an arrangement located on the intervening side,
The rectifying circuit is provided at a position connecting between the positive side of the output of the rectifying circuit and the main diode on the positive electrode side, and between the capacitor on the positive electrode side and the capacitor on the negative electrode side. A positive electrode side switching element forming a circuit connecting both ends of the negative electrode side capacitor and both ends of the negative electrode side capacitor,
The rectifying circuit is provided at a position connecting between the negative side of the output of the rectifying circuit and the main diode on the negative electrode side, and between the capacitor on the positive electrode side and the capacitor on the negative electrode side. A negative electrode side switching element forming a circuit connecting both ends of the positive electrode side capacitor and both ends of the positive electrode side capacitor,
The above-mentioned inverter circuit is provided with a single-pressure DC voltage, a double-pressure DC voltage corresponding to twice the single-pressure DC voltage, and an intermediate between the single-pressure DC voltage and the double-pressure DC voltage. To the computer that controls the booster circuit that supplies the DC voltage of any of the intermediate voltage that is the voltage of
By turning off both the positive side switching element and the negative side switching element, the booster circuit is controlled so that the single voltage DC voltage is supplied to the inverter circuit, and the positive side switching element and the negative side are used. By repeatedly switching on / off of one of the switching elements and turning off the other switching element, the booster circuit is controlled to supply the intermediate voltage, and the positive side switching is performed. By repeating on / off switching of these switching elements so that one of the switch of the element and the switching element on the negative side is turned on and the other switching element is turned off, the booster circuit has the double voltage. By controlling to supply the DC voltage, the booster circuit supplies the intermediate voltage from the state of supplying the single voltage DC voltage to the inverter circuit, and then supplies the double voltage DC voltage. , A program for controlling the booster circuit.

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