JPS6369460A - Rectifier circuit - Google Patents

Abstract

PURPOSE:To suppress rush current effectively, by a method wherein a plurality of inrush resistors are used and connected in series to a single-phase half-wave rectifier circuit. CONSTITUTION:A rectifier circuit of automatic changing type is composed of a switch 21, a resistor to suppress rush current at ON-state (inrush resistor) 3, a thyristor 4 changing single-phase half-wave rectifier type and voltage multiplying rectifier type, rectifier diodes 5-6, and first-second capacitors 7-8. When voltage of an AC power source 1 is higher than reference voltage, the thyristor 4 is turned off and the single-phase half-wave rectifier is constituted and power is supplied to a load 9. In this case, in addition to the inrush resistor 3, a second inrush resistor 10 is installed. In this constitution, in the single-phase half-wave rectifier at high input voltage state that the rush current becomes large, the first and second inrush resistors 3, 10 becomes sum of series connection thereby the rush current can be suppressed effectively, and consumption power of the resistor 3 at stable state can be made small.

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention relates to a rectifier circuit that can be switched between a single-phase half-wave rectifier circuit and a voltage doubler rectifier circuit.

[Conventional technology] FIG. 5 shows a conventional automatic switching type rectifier circuit.

In Fig. 5, (1) is an AC power supply, (2) is a switch, and (3) is a resistor that suppresses inrush current when switch (2) is turned on (hereinafter referred to as inrush resistance).
(4) is a thyristor that switches between a single-phase half-wave rectifier circuit type and a voltage doubler rectifier circuit type, (5) and (8) are rectifier diodes, and (7) and (8) are the first and second transistors connected in series. , and the second capacitor, (8) is the load.

The gate circuit (not shown) of the thyristor (4) turns off the thyristor (4) to form a single-phase half-wave rectifier circuit when the voltage of the AC power supply (1) is a high input voltage higher than the reference voltage. Further, in the case of a low input voltage lower than the reference voltage, the thyristor (4) is turned on to form a voltage doubler rectifier circuit.

Figure 6 shows the inrush current (11) in a single-phase half-wave rectifier circuit.
1214 Table ^zu Rokuji side 1 + z When the positive polarity is a < rp, the rush current (11) flows in the direction of the arrow, and the first charging circuit ( 12) is formed. At this time, the thyristor (0 is in the OFF state. When the AC power supply (1) has the opposite polarity, no current flows. In this way, single-phase half-wave rectification is performed.

Figures 7 and 8 show the inrush current (11
) shows the route. Here, when the AC power supply (1) has the positive polarity shown in Figure 7, the path of the rush current (11) is the same as in the case of a single-phase half-wave rectifier circuit (Fig. 6), and the path of the inrush current (11) is the same as in the case of a single-phase half-wave rectifier circuit (Fig. 6), and when the AC power supply (1) has the positive polarity shown in Figure 8, Now, the path of the AC power source (1) is shown by the arrow, and the path of the AC power source (1) is shown by the arrow, leading to the second charging circuit (13) that charges the second capacitor (8).
) is formed. Thus, the two capacitors (7)
, (8) is charged, and the AC power supply (1) is connected to the load (9).
A voltage twice as high as the voltage applied is applied.

6, 7, and 8, the inrush current (11
) is the current that charges the capacitor (7) or (8) when the switch (2) is turned on, and its peak value is related to the peak value of the AC power supply voltage when the switch (2) is turned on. It increases as the high price increases. In addition, the resistance value of the inrush resistor (3) limits the maximum peak value of the inrush current (11), and as the resistance value increases, the inrush current (11)
1) The maximum wave height value decreases.

In addition, in a steady state, that is, in a state where sufficient time has passed since the switch (2) is turned on, the current value of the current that charges the capacitor (7) or (8) (hereinafter referred to as "charging current") is Since (9) requires approximately constant power, it is determined by the voltage value across the load (9), and its path is equal to the path of the inrush current (11). Therefore, it is full.
The t current is the inrush current (11
) is the path for the inrush current (11) in Figures 7 and 8 in the case of a voltage doubler rectifier circuit, so the charge flowing through the inrush resistor (3) when the voltages across the load (3) are equal The current is.

The voltage is about twice as high when using a voltage doubler rectifier circuit as compared to when using a single-phase half-wave rectifier. Furthermore, even in the same rectifier circuit system, the voltage across the load (3) is lower when the input voltage is low, so the charging current flowing through the inrush resistor (3) becomes larger.

Therefore, when the AC power supply (1) has a high input voltage higher than the reference voltage, the inrush current is large and the charging current is small, and when the input voltage is low than the reference voltage, the inrush current is small and the charging current is large.

[Problems to be solved by the invention] In the conventional automatic switching rectifier circuit, one inrush resistor (3) has an inrush current limiting effect, and the inrush current in a single-phase half-wave rectifier circuit In order to suppress the resistance to an appropriate value, the resistance value of the inrush resistor cannot be made smaller than a certain value, and on the other hand, the power consumption of the inrush resistor must be twice as large as the charging current compared to a single-phase half-wave rectifier circuit. Since the voltage rectifier circuit is larger, there is a problem in that the power capacity of the inrush resistor needs to be increased.

This invention was made to solve the above problems, and the resistance value of the inrush resistor against the inrush current is made large in a single-phase half-wave rectifier circuit and small in a voltage doubler rectifier circuit. The purpose is to obtain a rectifier circuit that can use a much smaller inrush resistance.

[Means for Solving the Problems] A rectifier circuit according to the present invention includes a first charging circuit that charges a first capacitor when an AC power source has positive polarity, and a plurality of inrush resistors that limit an inrush current. are connected in series, and some of the plurality of inrush resistors are connected to a second charging circuit that charges the second capacitor when the AC power source has reverse polarity and its voltage is lower than the reference voltage. has been done. .

[Function] According to the present invention, when the single-phase half-wave rectifier circuit charges the first charging circuit, inrush current is suppressed by the plurality of inrush resistors connected in series, and the first and second charging circuits are When charging the voltage doubler rectifier circuit, current mainly flows through only a portion of the inrush resistor, so power consumption by the inrush resistor is suppressed.

Description 1, Name of the invention Rectifier circuit 2, Claims (1) When the first and second capacitors are connected in series, and the voltage of the AC power supply is higher than the reference voltage, the above-mentioned first It becomes a single-phase half-wave rectifier circuit by charging the capacitor of
When the voltage of the AC power supply is lower than the reference voltage, the first
and a rectifier circuit that charges the second capacitor and becomes a voltage doubler rectifier circuit, the first charging circuit that charges the first capacitor when the AC power source has positive polarity, and a plurality of resistors that limit inrush current. The resistors are connected in series, and some of the plurality of resistors are connected to a second charging circuit that charges the second capacitor when the AC power source has opposite polarity and the voltage thereof is lower than the reference voltage. A rectifier circuit characterized by:

3. Detailed Description of the Invention [Field of Industrial Application] This invention relates to a rectifier circuit that can be switched between a single-phase half-wave rectifier circuit and a voltage doubler rectifier circuit.

[Conventional technology] FIG. 5 shows a conventional automatic switching type rectifier circuit.

In Fig. 5, (1) is an AC power supply, (2) is a switch, and (3) is a resistor that suppresses the inrush current of switch (2) at 08:00 (hereinafter referred to as inrush resistance).
(4) is a thyristor that switches between a single-phase half-wave rectifier circuit type and a voltage doubler rectifier circuit type, (5) and (8) are rectifier diodes, and (7) and (8) are series-connected thyristors.
and a second capacitor, (9) is a load.

The gate circuit (not shown) of the thyristor (4) turns off the thyristor (4) to form a single-phase half-wave rectifier circuit when the voltage of the AC power supply (1) is a high input voltage higher than the reference voltage. Further, in the case of a low input voltage lower than the reference voltage, the thyristor (4) is turned on to form a voltage doubler rectifier circuit.

Figure 6 shows the inrush current (11) in a single-phase half-wave rectifier circuit.
To Table 2 + 4 Table 4 Rokuwan Gaku r1) to M broom ＾正瑞In addition, in each figure, the same reference numerals indicate the same or equivalent parts.

Claims (1)

[Claims] (1) It has a first and second capacitor connected in series, and when the voltage of the AC power source is higher than the reference voltage, the first capacitor is charged to form a single-phase half-wave rectifier circuit,
When the voltage of the AC power source is lower than the reference voltage, the first
and a rectifier circuit that charges the second capacitor and becomes a voltage doubler rectifier circuit, the first charging circuit that charges the first capacitor when the AC power source has positive polarity, and a plurality of resistors that limit inrush current. The resistors are connected in series, and some of the plurality of resistors are connected to a second charging circuit that charges the second capacitor when the AC power source has opposite polarity and its voltage is lower than the reference voltage. A rectifier circuit characterized by: