JP2011044036A - Ac current controller and control method and program for ac current - Google Patents

Abstract

An alternating current control device is provided that can be connected in series between a power source and a load to delay a current phase with low loss.
An alternating current control device includes a full bridge type MERS and a control means, and is used by being connected in series between an inductive load and an alternating current power source. The full bridge type MERS 100 is a bridge circuit composed of four reverse conducting semiconductor switches SW1 to SW4, and a capacitor CM is connected between the DC terminals. The control means 300 switches ON / OFF of the reverse conducting semiconductor switch SW2 and the reverse conducting semiconductor switch SW3 every half cycle of the AC voltage. The alternating current control device 1 delays the phase of the alternating current by alternately switching ON / OFF of the reverse conducting semiconductor switch SW1 and the reverse conducting semiconductor switch SW3.
[Selection] Figure 1

Description

  The present invention relates to an alternating current control device, an alternating current control method, and a program.

  2. Description of the Related Art A full-bridge magnetic energy recovery switch (MERS: Magnetic Energy Recovery Switch) (hereinafter referred to as “full-bridge MERS”) is known as a device that controls the phase of a conducting current.

  The full-bridge MERS is composed of four reverse conducting semiconductor switches and one capacitor. Full-bridge MERS can control current by simple control.

Patent Document 1 discloses an AC voltage control device that controls an AC voltage applied to an inductive load by advancing the current phase of an AC power supply using a full-bridge MERS.
This AC voltage control device is connected in series between an AC power source and an inductive load.
In addition, this AC voltage control device includes two reverse conducting semiconductor switches arranged on the diagonal line of the bridge circuit of the full bridge type MERS as one pair, and ON / OFF of the two pairs of reverse conducting semiconductor switches. Switch off. ON / OFF switching of the reverse conducting semiconductor switch is performed in synchronization with the phase of the voltage of the AC power supply.
However, the timing for switching ON / OFF of the reverse conducting semiconductor switch can be earlier than the timing of the zero crossing when the positive / negative of the output voltage of the AC power supply is switched.
Accordingly, the AC voltage control device described in Patent Document 1 can advance the current phase.
Further, since the current phase of the AC power supply is advanced, the phase of the AC voltage applied to the resistance of the inductive load is advanced.

JP 2007-058676 A

However, in the AC voltage control device described in Patent Document 1, if the phase of the current supplied to the load is delayed, there is a problem that unnecessary power loss occurs.
In the AC voltage control device described in Patent Document 1, when the reverse conduction type semiconductor switch of the full-bridge MERS is switched at a timing later than the timing at which the voltage of the AC power supply crosses zero, the phase of the conducting current can be delayed. However, when the reverse conduction type semiconductor switch of the full bridge type MERS is switched at a timing later than the timing at which the voltage of the AC power supply crosses zero, the capacitor of the full bridge type MERS is short-circuited. When the capacitor is short-circuited, the charge accumulated in the capacitor is discharged, and the AC voltage control device loses power.

  Therefore, in order to delay the phase of the current that conducts the full-bridge MERS of this AC voltage control device without unnecessary power loss, the reverse-conductivity semiconductor of the full-bridge MERS is not short-circuited in a state where the capacitor is charged. You need to control the switch.

  The present invention has been made in view of the above-described problems, and an alternating current that can delay the phase of a current that conducts a full-bridge MERS without short-circuiting the full-bridge MERS capacitor in a charged state. It is an object to provide a control device, a control method, and a program.

In order to achieve the above object, an alternating current control device according to the first aspect of the present invention provides:
Inserted in series between the AC power source and the inductive load, the first AC terminal is connected to the anode of the first diode and the cathode of the second diode, and the cathode of the first diode is connected to the third diode. The cathode of the diode and the positive electrode of the capacitor are connected, the anode of the second diode is connected to the anode of the fourth diode and the negative electrode of the capacitor, and the anode of the third diode and the cathode of the fourth diode Are connected to a second AC terminal, a first self-extinguishing element is connected in parallel to the first diode, and a second self-extinguishing element is connected in parallel to the second diode. , A third self-extinguishing element is connected in parallel to the third diode, and a fourth self-extinguishing element is connected in parallel to the fourth diode. · By is switched OFF, and the magnetic energy recovery switch for storing and regenerating the magnetic energy stored in the reactance of the inductive load as electrostatic energy in the capacitor,
Control means for controlling ON / OFF of each self-extinguishing element;
With
The control means always turns off the two self-extinguishing elements among the four self-extinguishing elements and turns on / off the other two self-extinguishing elements. In this case, control is performed at a timing later than the timing at which the voltage of the AC power supply crosses zero so that the other is turned off.
It is characterized by that.

  For example, the control means always turns off the first and second self-extinguishing elements, and turns on and off the third and fourth self-extinguishing elements. Control may be performed at a timing later than the timing at which the voltage of the AC power supply crosses zero so that the other is turned off.

For example, it further comprises timing setting means for setting the timing,
The control means may control ON / OFF of the self-extinguishing element at the timing set by the timing setting means.

Furthermore, the control means includes
Switch on / off of the self-extinguishing element at a timing earlier than the timing at which the voltage of the AC power supply crosses zero,
When switching the self-extinguishing element at the early timing, when the first self-extinguishing element and the fourth self-extinguishing element are ON, the second self-extinguishing element and When the third self-extinguishing element is controlled to be turned off and the second self-extinguishing element and the third self-extinguishing element are on, the first self-extinguishing element is turned on. The arc type element and the fourth self-extinguishing type element may be controlled to be turned off.

A power factor measuring means for measuring the power factor of the AC power source and outputting the measured power factor;
The control unit may feed back the power factor output from the power factor measurement unit and control ON / OFF of the self-extinguishing element so that the power factor becomes a desired value.

  For example, each of the diodes may be a parasitic diode built in the self-extinguishing element connected in parallel.

Moreover, the alternating current control method according to the second aspect of the present invention includes:
Inserted in series between the AC power source and the inductive load, the first AC terminal is connected to the anode of the first diode and the cathode of the second diode, and the cathode of the first diode is connected to the third diode. The cathode of the diode and the positive electrode of the capacitor are connected, the anode of the second diode is connected to the anode of the fourth diode and the negative electrode of the capacitor, and the anode of the third diode and the cathode of the fourth diode Are connected to a second AC terminal, a first self-extinguishing element is connected in parallel to the first diode, and a second self-extinguishing element is connected in parallel to the second diode. , A third self-extinguishing element is connected in parallel to the third diode, and a fourth self-extinguishing element is connected in parallel to the fourth diode. · OFF by switches, a magnetic energy regeneration switch for storing and regenerating magnetic energy stored in the reactance of the inductive load as electrostatic energy in the capacitor,
Of the four self-extinguishing elements, two of the self-extinguishing elements are always turned OFF, and the other two self-extinguishing elements are turned ON / OFF. Control at a timing later than the timing at which the voltage of the AC power supply crosses zero so as to be OFF,
It is characterized by that.

The program according to the third aspect of the present invention is
Inserted in series between the AC power source and the inductive load, the first AC terminal is connected to the anode of the first diode and the cathode of the second diode, and the cathode of the first diode is connected to the third diode. The cathode of the diode and the positive electrode of the capacitor are connected, the anode of the second diode is connected to the anode of the fourth diode and the negative electrode of the capacitor, and the anode of the third diode and the cathode of the fourth diode Are connected to a second AC terminal, a first self-extinguishing element is connected in parallel to the first diode, and a second self-extinguishing element is connected in parallel to the second diode. , A third self-extinguishing element is connected in parallel to the third diode, and a fourth self-extinguishing element is connected in parallel to the fourth diode. By switching OFF, the first to fourth self-extinguishing elements of the magnetic energy regenerative switch that stores and regenerates the magnetic energy stored in the reactance of the inductive load as electrostatic energy by the capacitor A program for controlling OFF,
On the computer,
Of the four self-extinguishing elements, two of the self-extinguishing elements are always turned OFF, and the other two self-extinguishing elements are turned ON / OFF. A control function for controlling at a timing later than the timing at which the voltage of the AC power supply crosses zero so as to be OFF,
It is characterized by realizing.

  According to the present invention, in a full bridge type MERS circuit connected in series between an AC power supply and a load, not only the phase of the current supplied to the load can be advanced but also delayed.

It is a circuit diagram which shows the structure of the alternating current control apparatus which concerns on embodiment of this invention. It is a figure which shows the example of the control means of the alternating current control apparatus shown in FIG. It is a circuit diagram which shows the state which connected the alternating current control apparatus shown in FIG. 1 in series between AC power supply and load. It is a figure which shows the correspondence of ON / OFF of the switch accompanying the switching operation which the switching apparatus shown in FIG. 3 performs. It is a figure which shows operation | movement of the alternating current control apparatus at the time of performing control which advances an electric current phase. FIG. 4 is a diagram illustrating a relationship between a power supply voltage and a load current associated with a time transition in a case where control for advancing a current phase is performed in the circuit diagram illustrated in FIG. It is a figure which shows operation | movement of the alternating current control apparatus at the time of performing control which delays an electric current phase. It is a figure which shows operation | movement of the alternating current control apparatus accompanying switching of a switch in case an electric current flows from the power supply side to the load side. It is a figure which shows operation | movement of the alternating current control apparatus accompanying switching of a switch in case an electric current flows from the load side to the power supply side. It is a figure which shows the transition of how the electric current flows with time transition. FIG. 4 is a diagram illustrating a relationship between a power supply voltage and a load current with a time transition in a case where control is performed to delay a current phase in the circuit diagram illustrated in FIG. 3.

  Hereinafter, an alternating current control device according to an embodiment of the present invention will be described with reference to the drawings.

With reference to FIG. 1, the alternating current control apparatus 1 which concerns on embodiment of this invention is demonstrated.
The alternating current control device 1 includes a full bridge type MERS 100, a power factor meter 200, a control means 300, a terminal 101, and a terminal 102.

The full bridge type MERS 100 includes four reverse conducting semiconductor switches SW1 to SW4, a capacitor CM, AC terminals AC1 and AC2 (AC: Alternating Current), and DC terminals DCP and DCN (DC: Direct Current). Bridge circuit.
A power factor meter 200 is connected to the AC terminal AC1, and a terminal 102 is disposed on the AC terminal AC2 side.

The reverse conducting semiconductor switch SW1 includes an N-channel silicon MOSFET (FET) including a switch unit SSW1 that switches on / off of a forward current and a diode unit DSW1 connected in parallel with the switch unit SSW1. : Field Effect Transistor).
The switch unit SSW1 includes a gate GSW1, and is fired when the ON signal is input to the gate GSW1, and becomes conductive when the OFF signal is input to the gate GSW1.

  Similarly, the reverse conducting semiconductor switch SW2 includes the switch unit SSW2 and the diode unit DSW2, the reverse conducting semiconductor switch SW3 includes the switch unit SSW3 and the diode unit DSW3, and the reverse conducting semiconductor switch SW4 includes the switch unit SSW4 and the diode unit. Each switch unit is switched ON / OFF by a signal input to the gates GSW2, GSW3, and GSW4.

The AC terminal AC1 is connected to the anode of the diode part DSW1 and the cathode of the diode part DSW2.
The DC terminal DCP is connected to the cathode of the diode part DSW1, the cathode of the diode part DSW3, and the positive electrode of the capacitor CM.
The DC terminal DCN is connected to the anode of the diode part DSW2, the anode of the diode part DSW4, and the negative electrode of the capacitor CM.
The AC terminal AC2 is connected to the anode of the diode part DSW3 and the cathode of the diode part DSW4.

The capacitor CM stores the magnetic energy stored in the reactance in the circuit as electrostatic energy. The capacitor CM is composed of, for example, an electrolytic capacitor having polarity.
The capacitor CM is connected between the DC terminals DCP-DCN of the full bridge type MERS100.

It is preferable that the resonance frequency of series resonance between the capacitor CM and the reactance in the circuit is higher than the output frequency of the AC power supply 500.
When the resonance frequency is higher, charging / discharging of the capacitor CM is completed within a half cycle of the output voltage of the AC power supply, so that control when the current phase is advanced is simplified.

  The power factor meter 200 is connected in series between the AC terminal AC1 and the terminal 101 of the full bridge type MERS100. The power factor meter 200 measures the power factor from the phase of the conducting current and the phase of the voltage, and outputs the measured power factor information to the control means 300.

  The control means 300 controls ON / OFF of the switch sections SSW1 to SSW4 of the reverse conducting semiconductors SW1 to SW4 in synchronization with the AC voltage output from the AC power supply 500. The control means 300 operates when an AC voltage is applied.

  The control means 300 reads the phase of the applied AC voltage, and switches on / off the switch units SSW1 to SSW4 based on the read phase of the AC voltage.

The control means 300 outputs an ON signal or an OFF signal to the gates GSW1 to GSW4, respectively.
In this embodiment, since the reverse conducting semiconductor is an N-channel type MOSFET, the ON signal is a voltage higher than the threshold voltage, and the OFF signal is a voltage lower than the threshold voltage.
The control means 300 is composed of, for example, a comparator, a flip-flop, a timer, and the like, and outputs a control signal with the phase shifted by α by the timer when the change in the polarity of the input voltage is detected by the comparator.

The control means 300 controls ON / OFF of the switch sections SSW1 to SSW4 every half cycle of one cycle of the applied AC voltage.
The control means 300 controls the ON / OFF timing by changing the parameter α that determines the ON / OFF control timing.
The control means 300 automatically sets the timing for turning on / off the switch by changing the parameter α by an automatic mode for controlling the timing for turning on / off the switch by automatically changing the parameter α. There is a mode.

In the automatic mode, the control unit 300 performs a switching operation based on the applied AC voltage and the power factor output from the power factor meter 200.
The control means 300 includes a memory, and stores a power factor desired by the user in the memory. The control unit 300 includes an input unit that stores a power factor desired by the user in a memory. When the user inputs a desired power factor to the input means, the input value is stored in the memory.
The control unit 300 in the automatic mode feeds back the power factor output from the power factor meter 200 so that the power factor output from the power factor meter 200 becomes a desired power factor stored in the memory, and sets the parameter α. Adjust automatically.

  In the manual mode, the control means 300 is set by the user with a parameter α for switching ON / OFF of the switch units SSW1 to SSW4. The set parameter α is stored in the memory. The control means 300 controls ON / OFF of the switch units SSW1 to SSW4 based on the set parameter α and the phase of the applied AC voltage.

For example, as shown in FIG. 2, the control means 300 is an apparatus provided with a dial 310 as means for setting α.
The parameter α is set in the forward direction by turning the dial 310 clockwise (CW: Clockwise), and the parameter α is set in the delay direction by rotating counterclockwise (CCW: Counter Clockwise). According to the set parameter α A control signal is input to the gates GSW1 to GSW4 through a conducting wire (not shown).

  FIG. 3 shows an example of use in which the AC power supply 500 is connected to the terminal 101 and the load 400 is connected to the terminal 102 of the AC current control device 1 shown in FIG.

The AC power supply 500 has a cycle of 2π (rad) and an effective voltage of 100V.
Further, the control means 300 is connected to an AC power source 500, and an AC voltage output from the AC power source 500 is applied. The control means 300 performs a switching operation based on the AC voltage applied from the AC power source 500.

  The load 400 is connected between the terminal 102 and the ground, and includes a resistor R and a reactance L.

  Here, FIG. 4 shows a correspondence diagram of ON / OFF of the switch units SSW1 to SSW4 accompanying the switching operation of the control means 300. As shown in FIG.

α is an angle of a value from −π (rad) to π (rad), and is a parameter for the control means 300 to shift the current phase.
That is, α represents the start phase of switching on / off.
Θ (rad) is a value indicating the phase of the AC voltage output from the AC power supply 500. θ is 2π (rad) in one cycle, and the reference phase is set to 0 (rad) when the value of the AC voltage output from the AC power supply 500 changes from negative to positive.

When performing control to advance the current phase, α is set to be positive. If the value of α is positive, the control means 300 turns on the switch unit SSW2 and the switch unit SSW3 and turns off the switch unit SSW1 and the switch unit SSW4 when θ is from −α to −α + π.
Further, when θ is from −α + π to −α + 2π, the control unit 300 turns on the switch unit SSW1 and the switch unit SSW4 and turns off the switch unit SSW2 and the switch unit SSW3.

When delaying the current phase, α is set negative. When the value of α is negative, the control unit 300 turns on the switch unit SSW1 and turns off the switch unit SSW2 when θ is from −α to −α + π.
Further, when θ is from −α + π to −α + 2π, the control unit 300 turns on the switch unit SSW2 and turns off the switch unit SSW1.
In this case, the switch unit SSW3 and the switch unit SSW4 are always OFF.

Next, the transition of the circuit of the alternating current control device 1 accompanying the switching operation when α is positive will be described with reference to FIG. When α is positive, the alternating current control device 1 alternately repeats the states shown in FIGS. 5 (a) and 5 (b).
In the following drawings, whether each switch is ON or OFF is shown at the gate of each switch.
Further, when the switch is ON, the switch is indicated by a solid line and the diode is indicated by a dotted line, and when the switch is OFF, the switch is indicated by a dotted line and the diode is indicated by a solid line.

  The pair of switch unit SSW2 and switch unit SSW3 and the pair of switch unit SSW1 and switch unit SSW4 repeat ON / OFF every half cycle. As shown in FIG. 5A, when θ is from −α to −α + π, the switch unit SSW2 and the switch unit SSW3 are ON, and the switch unit SSW1 and the switch unit SSW4 are OFF. Also, as shown in FIG. 5B, when θ is from −α + π to −α + 2π, the switch unit SSW2 and the switch unit SSW3 are OFF, and the switch unit SSW1 and the switch unit SSW4 are ON.

Actually, in the circuit of FIG. 3, FIG. 6 shows the relationship between the power supply voltage and the load current when the control means 300 is controlled at α = 2π / 3 (rad), that is, α = 120 (°).
The load 400 is adjusted as a delay power factor of 0.7.

FIG. 6 is a diagram showing changes due to the load current, the power supply voltage, and the ON / OFF time transition of the switch units SSW1 to SSW4.
In FIG. 6A, the value obtained by multiplying the power supply voltage (V) by 0.1 and the value of the load current (A) are plotted against the transition of time (ms).
In FIG. 6B, the ON / OFF states of the switch units SSW1 to SSW4 are plotted with respect to time.
The time on the horizontal axis is common. One scale is 12.5 ms.

At T1, which is 120 (°) earlier than T0 when the value of the power supply voltage changes from negative to positive, the control unit 300 turns ON / OFF the pair of the switch unit SSW2 and the switch unit SSW3 and the pair of the switch unit SSW1 and the switch unit SSW4. Switch.
In order to prevent all of the switch units SSW1 to S4 from being turned on, the timing for turning on the switch unit is controlled later than the timing for turning off the switch unit.
Paying attention to the power supply voltage and the load current in FIG. 6A, it can be seen that the phase of the load current is ahead of the phase of the power supply voltage. Therefore, since the load 400 is adjusted to the delay power factor 0.7, it can be seen that the power factor has changed in the advance direction by the AC current control device 1.

Next, transition of the state of the alternating current control device 1 associated with the switching operation when α is negative will be described with reference to FIG. When α is negative, the alternating current control device 1 alternately repeats the states shown in FIGS. 7A and 7B.
When the switch part is ON, the switch part is indicated by a solid line and the diode part is indicated by a dotted line, and when the switch part is OFF, the switch part is indicated by a dotted line and the diode part is indicated by a solid line.

The control means 300 repeats ON / OFF of the switch unit SSW1 and the switch unit SSW2 every half cycle while always turning off the switch unit SSW2 and the switch unit SSW3.
As shown in FIG. 7A, when θ is from −α to −α + π, the switch unit SSW1 is ON and the other switches are ON.
As shown in FIG. 7B, when θ is from −α + π to −α + 2π, the switch unit SSW2 is ON and the other switches are OFF.
The alternating current control device 1 alternately repeats the states shown in FIGS. 7 (a) and 7 (b).

Next, based on the circuit shown in FIG. 7, the flow of current accompanying the switching operation when the current flows from the power supply side to the load side and when the current flows from the load side to the power supply side is shown in FIGS. As shown in FIG.
In FIGS. 8 and 9, in order to make it easy to understand how the current flows, elements and lines through which current flows are indicated by solid lines, and elements and circuits that do not flow are indicated by dotted lines.

  First, with reference to FIG. 8, a qualitative description will be given of how the current flows from the power supply side to the load side in the switching operation in which α is negative.

  When the switch unit SSW2 is ON, as shown in FIG. 8A, current is conducted from the power supply side to the load side (phase PR1). The current passes through the switch unit SSW2 and the diode unit DSW4.

When the power supply voltage is higher than the voltage of the capacitor CM when the switch unit SSW1 is ON, electric charge is accumulated in the capacitor CM as shown in FIG. 8B (phase PR2). The current flowing from the power source side passes through the switch unit SSW1 and flows into the positive electrode of the capacitor CM. Electric charge is accumulated in the capacitor CM, and the current flowing out from the negative electrode of the capacitor CM flows through the load 400 through the diode part DSW4.
However, when the voltage of the capacitor CM becomes equal to or higher than the power supply voltage, as shown in FIG. 8C, no charge is accumulated in the capacitor CM and the current is cut off (phase PR3).

  Next, with reference to FIG. 9, a qualitative description will be given of how the current flows from the load side to the power source side in the switching operation in which α is negative.

  When the switch unit SSW1 is ON, as shown in FIG. 9A, a current flows from the load side to the power source side (phase PL1). The current passes through the diode part DSW2 and the switch part SSW1.

When the switch unit SSW2 is ON, if the absolute value of the power supply voltage is higher than the voltage of the capacitor CM, as shown in FIG. 9B, charges are accumulated in the capacitor CM (phase PL2). The current flowing from the load side passes through the diode part DSW3 and flows into the positive electrode of the capacitor CM. The electric charge is accumulated in the capacitor CM, and the current flowing out from the negative electrode of the capacitor CM flows through the power source 500 through the switch unit SSW2.
However, when the voltage value of the capacitor CM becomes equal to or greater than the absolute value of the power supply voltage, as shown in FIG. 9C, no charge is accumulated in the capacitor CM and the current is cut off (phase PL3).

Actually, the transition to the state where charges are accumulated (phase PR2, phase PL2) occurs only several times.
Since the electric charge accumulated in the capacitor CM is not discharged, the voltage of the capacitor CM substantially matches the maximum value of the power supply voltage. Therefore, since the power supply voltage does not exceed the voltage of the capacitor CM, a state where charges are accumulated (phase PR2, phase PL2) is not achieved.
Therefore, when the switch unit SSW1 is ON, the current flowing from the power source side to the load side is blocked (phase PR3), and when the switch unit SSW2 is ON, the current flowing from the load side to the power source side is blocked (phase PL3). .

In the above, with reference to FIGS. 8 and 9, the flow of current accompanying the switching operation when α is negative has been described.
Next, FIG. 10 shows the transition of the current flow over time when α is negative with reference to the current flow accompanying the switching operation described with reference to FIGS.
However, it is assumed that the voltage of the capacitor CM matches the maximum value of the power supply voltage. Therefore, the charge accumulation state (phase PR2, phase PL2) is not considered.
Note that the current conduction state (phase PR1) shown in FIG. 10A corresponds to the current conduction state (phase PR1) shown in FIG. 8A.
Moreover, the electric current interruption state (phase PL3) shown in FIG.10 (b) respond | corresponds to the electric current interruption state (phase PL3) shown in FIG.9 (c).
Further, the current conduction state (phase PL1) illustrated in FIG. 10C corresponds to the current conduction state (phase PL1) illustrated in FIG. 9A.
Further, the current interruption state (phase PR3) shown in FIG. 10D corresponds to the current interruption state (phase PR3) shown in FIG. 8C.

  Since the value of α is from −π (rad) to 0 (rad), the power supply voltage is positive when the switch unit SSW2 is turned on. Therefore, when the switch unit SSW2 is turned on, the power supply voltage is positive, so that a current flows from the power supply side to the load side (phase PR1).

  As the power supply voltage changes, the value of the current decreases, and current gradually flows from the load side to the power supply side. However, when the switch unit SSW2 is ON, no current flows from the load side to the power source side, so the current is cut off (phase PL3).

  The shut-off state (phase PL3) continues, and then the switch unit SSW2 is turned off and the switch unit SSW1 is turned on. Since the value of α is from −π (rad) to 0 (rad), the power supply voltage is negative when the switch unit SSW1 is turned on. Therefore, when the switch unit SSW1 is turned on, since the power supply voltage is negative, a current flows from the load side to the power supply side (phase PL1).

  The current flows from the load side to the power supply side, and the current gradually flows from the power supply side to the load side as the power supply voltage changes. However, when the switch unit SSW1 is ON, no current flows from the power source side to the load side, so that the current is interrupted (phase PR3).

  Again, the switch unit SSW2 is turned on to enter a conductive state from the power source side to the load side (phase PR1), the current from the load side to the power source side is interrupted (phase PL3), and the switch unit SSW1 is turned on to load side From the power source side to the load side is interrupted (phase PR3).

  As described above, the current flowing through the full-bridge MERS 100 is connected from the power source side to the load side (phase PR1) → current cutoff from the load side to the power source side (phase PL3) → conduction from the load side to the power source side (phase PL1) → current interruption from the power source side to the load side (phase PR3) → conduction from the power source side to the load side (phase PR1) →...

Actually, in the circuit shown in FIG. 3, the relationship between the power supply voltage and the load current when the switching operation is controlled with α = −2π / 3 (rad), that is, α = −120 (°) is shown in FIG. .
However, the load 400 is adjusted to a delay power factor of 0.7.

FIG. 11A is a graph in which the value of the load current (A) and the value of 0.1 times the power supply voltage (V) are plotted with respect to time.
FIG. 11B is a graph in which the ON / OFF state of the switch unit SSW1 and the ON / OFF state of the switch unit SSW2 are plotted with respect to the transition of time.
FIG. 11C is a graph showing a change with time of the voltage of the capacitor CM.
The time (ms) on the horizontal axis is common.
As shown in FIG. 11 (a), the control means 300 is connected to the switch section SSW1 as shown in FIG. 11 (b) at a time T1 120 (°) later than the time T0 when the power supply voltage becomes negative to positive. Switch on / off of the switch section SSW2.

Focusing on the ON / OFF of the switch in FIG. 11B and the load current in FIG. 11A, as described with reference to FIG. 10, the current starts to be conducted every time the switch is switched, and the current gradually increases. It turns out that becomes a cutoff state.
Further, since the current phase is delayed by 120 (°) or more with respect to the delayed power factor 0.7 (approximately 45 °) of the load 400, it can be seen that the power factor changes in the delay direction.

It can also be seen that the capacitor CM is not discharged. As described with reference to FIGS. 8 and 9, the voltage of the capacitor CM is maintained in the vicinity of approximately 141 V, which is the maximum value of the AC voltage having an effective value of 100 V.
That is, since the capacitor CM does not discharge, power is not lost when the capacitor CM is short-circuited.

  As described above, according to the present embodiment, in the alternating current control device 1 using the full bridge type MERS 100, the current phase delay control can be performed without short-circuiting the capacitor CM.

  Therefore, by using the full-bridge MERS 100, it is possible to perform control for advancing the current phase and control for delaying it while preventing power loss due to the short circuit of the capacitor CM.

  In carrying out the present invention, various forms are conceivable and the present invention is not limited to the above embodiment.

  For example, in the above-described embodiment, the reverse conducting semiconductor switches SW1 to SW4 have been described as N-channel MOSFETs composed of switches and diodes. However, the reverse conduction type semiconductor switches SW1 to SW4 may be reverse conduction type switches, and are a field effect transistor, an insulated gate bipolar transistor (IGBT), a gate turn-off thyristor (GTO: Gate Turn-). Off thyristor) or a combination of a diode and a switch.

  Further, in the above embodiment, when the current phase is delayed, the switch unit SSW3 and the switch 2 are alternately turned ON / OFF, but the switch unit SSW1 and the switch unit SSW2 may be alternately turned ON / OFF.

  Further, the capacitor CM has been described as an electrolytic capacitor having polarity. However, the capacitor CM only needs to have a capacity to absorb magnetic energy, and need not have polarity. For example, the capacitor CM may be a ceramic capacitor or a plastic film capacitor.

  Further, the load 400 has been described as an inductive load including a resistance R and a reactance L, but the load 400 may be an incandescent lamp or a motor.

If the load 400 is an incandescent lamp, the brightness can be adjusted by delaying the current phase. It is possible to reduce power consumption by dimming. If a large number of incandescent lamps are installed, the power factor should always be dimmed around 1 by adjusting the number of light bulbs that adjust the phase by adjusting the number of light bulbs that adjust the phase and delay the phase. And so on.
In this case, dimming can be performed in the manual mode, or dimming may be performed in the automatic mode.
Particularly when dimming in the automatic mode, an illuminometer immediate means for measuring illuminance is further provided, the relationship between the target power factor and illuminance is stored in the memory of the control means 300, and the measured illuminance is fed back. The control means 300 may change the output phase of the power supply so that the illuminance becomes.

  If the load 400 is a plurality of motor groups, the current can be reduced by either method by appropriately selecting a motor that advances the current phase and a motor that delays the current phase, and the rotational torque can be controlled. It is possible to control the power factor and current of an induction motor operated under various load conditions manually or automatically as in the case of the dimming described above. This is particularly effective for motors that require a large amount of rush current for starting. When interrupting the use of the motor, if the motor is interrupted by reducing the rotational torque with the AC current control device of the present invention without stopping the motor rotation, the power required for starting the motor at the start of the next use is reduced. Is done.

Moreover, although the effective value of the voltage of the alternating current power supply 500 to which the alternating current control device 1 is connected has been described as 100 V, the effective value of the voltage is not limited. For example, the alternating current control device 1 may be connected to an industrial power supply having an effective value of 400V.
For example, when it is desired to use in a three-phase AC power supply system, it can be dealt with by installing this apparatus in each phase.

Although the control unit 300 has been described as a circuit that performs the above-described control, a microcontroller (including a CPU (Central Processing Unit) and a storage unit such as a RAM (Random Access Memory) and a ROM (Read Only Memory) ( Hereinafter, it may be a computer such as “microcomputer”.
In particular, when the control means 300 is a microcomputer, if the reverse conduction type semiconductor switch and the microcomputer are combined so that the reverse conduction type semiconductor switch is turned ON / OFF with respect to signals 1 and 0 output from the microcomputer, Since the reverse conducting semiconductor switch can be switched on and off by output, the number of components can be reduced.
In this case, for example, a program for outputting the above-described gate signal may be stored in the microcomputer in advance.

  In addition, a computer-readable recording program such as a flexible disk, a CD-ROM (Compact Disc Read-Only Memory), a DVD (Digital Versatile Disk), and an MO (Magnetic Optical Disk) is recorded on the computer. The program may be stored and distributed on a medium, installed on another computer, operated as the above-described means, or the above-described steps may be executed.

  Furthermore, the program may be stored in an external storage device or the like included in a server device on the Internet, and may be downloaded onto a computer by being superimposed on a carrier wave, for example.

1 AC Current Control Device 100 Full Bridge Type MERS
200 Power factor meter 300 Control means 310 Dial 400 Load 500 AC power supply SW1, SW2, SW3, SW4 Reverse conducting semiconductor switch DSW1, DSW2, DSW3, DSW4 Diode section SSW1, SSW2, SSW3, SSW4 Switch section GSW1, GSW2, GSW3 GSW4 Gate CM capacitor

Claims (8)

Inserted in series between the AC power source and the inductive load, the first AC terminal is connected to the anode of the first diode and the cathode of the second diode, and the cathode of the first diode is connected to the third diode. The cathode of the diode and the positive electrode of the capacitor are connected, the anode of the second diode is connected to the anode of the fourth diode and the negative electrode of the capacitor, and the anode of the third diode and the cathode of the fourth diode Are connected to a second AC terminal, a first self-extinguishing element is connected in parallel to the first diode, and a second self-extinguishing element is connected in parallel to the second diode. , A third self-extinguishing element is connected in parallel to the third diode, and a fourth self-extinguishing element is connected in parallel to the fourth diode. · By is switched OFF, and the magnetic energy recovery switch for storing and regenerating the magnetic energy stored in the reactance of the inductive load as electrostatic energy in the capacitor,
Control means for controlling ON / OFF of each self-extinguishing element;
With
The control means always turns off the two self-extinguishing elements among the four self-extinguishing elements and turns on / off the other two self-extinguishing elements. In this case, control is performed at a timing later than the timing at which the voltage of the AC power supply crosses zero so that the other is turned off.
An AC current control device characterized by that. The control means always turns off the first and second self-extinguishing elements, turns on and off the third and fourth self-extinguishing elements, and when one is on, the other is Control at a timing later than the timing at which the voltage of the AC power supply crosses zero so as to be OFF,
The alternating current control apparatus according to claim 1. A timing setting means for setting the timing;
The control means controls ON / OFF of the self-extinguishing element at the timing set by the timing setting means.
The alternating current control apparatus according to claim 1 or 2, wherein The control means further includes
Switch on / off of the self-extinguishing element at a timing earlier than the timing at which the voltage of the AC power supply crosses zero,
When switching the self-extinguishing element at the early timing, when the first self-extinguishing element and the fourth self-extinguishing element are ON, the second self-extinguishing element and When the third self-extinguishing element is controlled to be turned off and the second self-extinguishing element and the third self-extinguishing element are on, the first self-extinguishing element is turned on. Controlling to turn off the arc-type element and the fourth self-extinguishing element,
The alternating current control apparatus according to any one of claims 1 to 3, wherein A power factor measuring means for measuring the power factor of the AC power source and outputting the measured power factor;
The control means feeds back the power factor output from the power factor measurement means and controls ON / OFF of the self-extinguishing element so that the power factor becomes a desired value.
The alternating current control apparatus according to any one of claims 1 to 4, wherein Each of the diodes is a parasitic diode built in the self-extinguishing element connected in parallel.
The alternating current control apparatus according to any one of claims 1 to 5, wherein Inserted in series between the AC power source and the inductive load, the first AC terminal is connected to the anode of the first diode and the cathode of the second diode, and the cathode of the first diode is connected to the third diode. The cathode of the diode and the positive electrode of the capacitor are connected, the anode of the second diode is connected to the anode of the fourth diode and the negative electrode of the capacitor, and the anode of the third diode and the cathode of the fourth diode Are connected to a second AC terminal, a first self-extinguishing element is connected in parallel to the first diode, and a second self-extinguishing element is connected in parallel to the second diode. , A third self-extinguishing element is connected in parallel to the third diode, and a fourth self-extinguishing element is connected in parallel to the fourth diode. · OFF by switches, a magnetic energy regeneration switch for storing and regenerating magnetic energy stored in the reactance of the inductive load as electrostatic energy in the capacitor,
Of the four self-extinguishing elements, two of the self-extinguishing elements are always turned OFF, and the other two self-extinguishing elements are turned ON / OFF. Control at a timing later than the timing at which the voltage of the AC power supply crosses zero so as to be OFF,
An alternating current control method characterized by the above. Inserted in series between the AC power source and the inductive load, the first AC terminal is connected to the anode of the first diode and the cathode of the second diode, and the cathode of the first diode is connected to the third diode. The cathode of the diode and the positive electrode of the capacitor are connected, the anode of the second diode is connected to the anode of the fourth diode and the negative electrode of the capacitor, and the anode of the third diode and the cathode of the fourth diode Are connected to a second AC terminal, a first self-extinguishing element is connected in parallel to the first diode, and a second self-extinguishing element is connected in parallel to the second diode. , A third self-extinguishing element is connected in parallel to the third diode, and a fourth self-extinguishing element is connected in parallel to the fourth diode. By switching OFF, the first to fourth self-extinguishing elements of the magnetic energy regenerative switch that stores and regenerates the magnetic energy stored in the reactance of the inductive load as electrostatic energy by the capacitor A program for controlling OFF,
On the computer,
Of the four self-extinguishing elements, two of the self-extinguishing elements are always turned OFF, and the other two self-extinguishing elements are turned ON / OFF. A control function for controlling at a timing later than the timing at which the voltage of the AC power supply crosses zero so as to be OFF,
A program characterized by realizing.

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