JP3063354B2 - General-purpose inverter - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a general-purpose inverter which can be commonly applied to AC power supplies having different voltages and different phases without changing the configuration of its main body.

[0002]

2. Description of the Related Art As a conventional general-purpose inverter of this type, if there are three types of AC power supply, for example, a single-phase 100V, a single-phase 200V, and a three-phase 200V, for each type of power supply to be applied. There are known ones dedicated to each series according to the voltage and the number of phases.

[0003]

However, in the above-mentioned conventional general-purpose inverters, although the basic circuit configuration and the control method are common, each of them has a dedicated series according to the type of the applied AC power supply. For those that are restricted in their use depending on the type of AC power supply, the advantages of the series can not be fully utilized, resulting in high price due to small-scale production, and furthermore, single-phase AC With respect to the power source, the required capacity of the capacitor for smoothing the rectified voltage is increased, which leads to an increase in the size and cost of the inverter as a whole device.

In view of the above, the present invention is applicable to AC power supplies having different voltages and different phases as described above, and is designed to be a series as a whole while suppressing an increase in the required installation space. It is intended to provide a general-purpose inverter that can be obtained.

[0005]

In order to achieve the above object, a general-purpose inverter according to the present invention is connected in parallel to a rectification unit forming a three-phase full-wave rectification circuit receiving an AC input and an output terminal of the rectification unit. In a general-purpose inverter including a smoothing unit including a rectified voltage smoothing capacitor and an inverter unit that outputs a required alternating current by inputting a rectified DC voltage smoothed by the smoothing capacitor, the smoothing unit includes two sets of the same capacity. A set of terminals formed by connecting capacitors in series, and drawn from a connection point between the two capacitors; and three sets of terminals drawn from a connection point between each phase upper and lower arms of the rectifier circuit forming a bridge structure. The AC input terminal having a short-circuit piece for short-circuiting any two of the three terminals; or in the inverter, Three sets of terminals respectively drawn from the connection points between the upper and lower arms of each phase of the rectifier circuit forming a ridge structure, a short-circuit piece for short-circuiting any two of the three sets of terminals, and an output of the rectifier circuit. An input terminal portion for the AC input having two sets of terminals respectively drawn from the positive and negative bipolar buses, and the smoothing portion is formed of a series connection of two sets of capacitors having the same capacity and is separately provided from the inverter. An input having a parallel connection of a capacitor and a fixed capacitor housed in the inverter, and further having three sets of terminals respectively drawn from both ends of the series connection and an intermediate connection point in relation to the attached capacitor. A terminal section is provided separately from the inverter, and the interconnection between the inverter, its AC power supply and the attached capacitor is made at both input terminal sections according to the type of the AC power supply. Shall be made, further without the said accessory capacitor and the input terminal unit so as unexpected accompanied an increase in the required installation space of the inverter is assumed to attach to a suitable surface of the rear surface or the like.

[0006]

In general, an inverter is basically composed of an AC input rectifying section, a smoothing section for an output rectified voltage thereof, and an inverter section for inputting a smoothed DC voltage via the smoothing section. The control circuit is shared regardless of the type of the AC input. Therefore, a series of general-purpose inverters that can be commonly applied to various AC inputs having different voltages and different numbers of phases can be realized by equalizing the smoothing section output voltages of the various inverters, that is, the inverter section input voltages. The input voltage applied to the rectifier and the smoothing unit of the inverter may be changed for each type of AC input to equalize the output voltage of the smoothing unit.

As described above, the first aspect of the present invention is intended for a single-phase or three-phase AC having a voltage ratio of 2, such as a single-phase 100 V, a single-phase 200 V, or a three-phase 200 V, as the AC input. Part is a three-phase full-wave rectifier circuit having a bridge configuration, and the smoothing part is a series connection of two sets of capacitors having the same capacity, and a connection point between the two capacitors is used as one of the application points of the AC input. In addition, the rated voltage of each component of each inverter is determined according to the maximum voltage during each AC input.
For example, if the applied AC input is three-phase 200 V, three-phase full-wave rectification is performed using all the arms of each phase of the three-phase full-wave rectifier circuit. A single-phase full-wave rectification is performed using the upper and lower arms for any two phases in the full-wave rectification circuit, and furthermore, if the AC input is, for example, a single-phase 100V, a terminal connection change in the input terminal portion is performed. , And the combination of the upper arm element of any one phase, the lower arm element of the other one phase, and the two sets of smoothing capacitors in the three-phase full-wave rectifier circuit. A set of single-phase half-wave rectifier circuits is formed in parallel with the single-phase AC input power supply, and connected so that the terminal voltages of the two capacitors have an additive polarity with each other, thereby doubling the single-phase AC input. Voltage rectification In which the obtaining a required DC voltage from both ends of the series connection of the capacitor. In order to perform the operation of changing the AC input application path as described above, one set of terminals drawn from a connection point between the two sets of capacitors and a connection point between the upper and lower arms of each phase of the three-phase full-wave rectifier circuit. 3 withdrawn
An input terminal portion having a set of terminals and a short-circuit piece for short-circuiting any two of the three sets of terminals is provided.

Further, the second embodiment of the present invention is directed to the same AC input as that of the first embodiment. However, the configuration of the rectifying voltage smoothing capacitor is the same as that of the first embodiment except that the capacity required at the time of three-phase AC input is reduced. A fixed capacitor housed in the inverter device and having a capacity obtained by excluding the three-phase AC input capacity from its required total capacity including a single-phase AC input, and being separately provided from the inverter. And the connection of the two capacitors having the same capacity is connected in series, and the connection point between the two capacitors is drawn out to an external terminal to connect the AC input of the inverter. According to the type, as in the case of the first invention, the operation of changing the AC input application path is performed. In addition, such separation of the installation place of the required capacitor
The required capacity of the rectifying voltage smoothing capacitor at the time of single-phase AC input is larger than that at the time of three-phase AC input, and a circuit configuration that can be commonly applied at the time of both AC inputs is three-phase. The purpose of the present invention is to cope with extra large size of the inverter in the AC input mode, and to remove the accessory capacitor as an option during the three-phase AC input mode. In order to perform the operation of changing the AC input application path as described above, three sets of terminals respectively drawn from the connection points between the upper and lower arms of each phase of the rectifier circuit forming a bridge, and one of the three sets of terminals. The inverter is provided with an input terminal portion of the AC input having a short-circuit piece for short-circuiting between two sets of terminals and two sets of terminals respectively drawn from the positive and negative bipolar buses on the output side of the rectifier circuit. An input terminal portion having three sets of terminals respectively drawn from both ends of the series connection and a connection point between both capacitors is provided.

Further, a third aspect of the present invention is that the attached capacitor of the second aspect of the present invention and its input terminal portion are mounted on an appropriate surface such as the back surface of the inverter with an increase in required installation space of the inverter. It is to be installed in a manner like a blank.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. FIGS. 1 to 3 correspond to the first invention, FIGS. 4 and 5 correspond to the second invention, FIG. 6 corresponds to the third invention, respectively, and FIGS. FIG. 2 is a circuit diagram of the inverter, FIG. 2 is a diagram showing a change in input terminal connection corresponding to the type of AC input corresponding to FIG. 1, FIG. 3 is an explanatory diagram of voltage doubler rectification operation at the time of single-phase AC input, and FIG. It is a perspective view of. In the respective drawings, the same reference numerals are given to components having the same function.

First, in FIG. 1, reference numeral 2 denotes a diode D ₁ .
Rectifying portion forming a three-phase full-wave rectifier circuit in the bridge configuration by D _6, 3 is a smooth portion formed of the series connection of the capacitor C ₁ and C ₂ of the same capacity. Reference numeral 4 denotes an inverter unit, which is composed of an inverter circuit having a three-phase bridge configuration of three upper and lower arms each having a switching element such as a power transistor having an antiparallel diode as an arm element, and capacitors C ₁ and C _{2 of the} smoothing unit 3. A DC voltage for driving the three-phase AC motor 6 is output from terminals U, V, and W using the DC voltage at both ends of the series connection of the DC motor as its input voltage. Further, reference numeral 1 denotes an input terminal portion, and terminals R, S, T drawn from connection points between the diodes D ₁ and D _4, between D ₂ and D _{5, and} between D ₃ and D _{6 of the} rectification unit 2 and the input terminals, respectively. The smoothing unit 3 has a terminal O drawn from a connection point between the capacitors C ₁ and C ₂ , and connects the inverter to the AC power supply 5.

Next, FIG. 2A shows a case where the AC power supply 5 supplies a single-phase (1φ) 100 V as 5a, and the terminals R, S,
The two terminals in T, for example, R and S are short-circuited, the 1φ100V is applied between the terminals R and O, and the diodes D ₁ and D
₂ , double rectification by two sets of single-phase half-wave rectifier circuits each combining the parallel connection of D ₄ and D _{5 and} the capacitors C ₁ and C ₂ , respectively, This is for obtaining a more required DC voltage, and the terminal T is not used.

FIG. 2B shows that the AC power supply 5
b shows a case where a single-phase (1φ) 200 V is supplied as b,
The input terminal unit 1 uses two terminals of R, S, and T except for the terminal O, for example, R and T, does not use the terminals O and S, and connects the AC input of 1φ200 V to the two terminals R and T. Through the rectifier 2 to perform single-phase full-wave rectification.

FIG. 2C shows that the AC power supply 5
The case where three-phase (3φ) 200V is supplied as c is shown,
In the input terminal section 1, the terminal O is not used and the 3φ20
The AC input of 0 V is applied to the rectifier 2 via terminals R, S and T to perform three-phase full-wave rectification. Next, FIG.
FIG. 3 illustrates the voltage doubling rectification operation of the single-phase AC input when the connection of the input terminal unit is changed as shown in FIG. 2A in the circuit diagram of FIG.
In contrast, two sets of single-phase half-wave rectifier circuits each comprising a parallel connection of diodes D ₁ and D ₂ and a capacitor C ₁ , a parallel connection of diodes D ₄ and D ₅ and a capacitor C ₂ are connected in parallel. And the terminal voltages V ₁ and V _{2 of the} capacitors C ₁ and C ₂ attenuated from the single-phase half-wave rectification maximum voltage value in accordance with the circuit time constants of the two rectifier circuits, respectively.
Are added so as to be added in the same polarity, and the sum V ₁ + V _{2 of} the two voltages is supplied to the inverter unit 4 as the double-voltage rectified output of the single-phase AC input. Note that illustration I ₁ and I ₂ are each charging current in the two single-phase half-wave rectifier circuit.

FIG. 4 corresponds to FIG.
There is shown a case of feeding the 1φ100V from the AC power supply 5a to the inverter, a smoothing portion 3a comprising a smoothing unit 3 in FIG. 1 from the fixed capacitor C _3, the capacitor C ₄₁ -C ₄₃ and C ₅₁ -C ₅₃ Are connected in parallel and are connected in series with two sets of capacitors having the same capacitance, and are separated and replaced by an auxiliary smoothing unit 3b provided separately from the inverter. An input terminal section 11 having three terminals P, N, and O respectively drawn from both ends of the series connection and an intermediate connection point thereof is newly provided. Further, the input terminal section 1 is pulled out from each part as shown in the drawing instead of the input terminal section 1. Terminals R, S, T, P, N
And a short circuit between the terminals R and S of the terminal unit 10 and a mutual connection between the corresponding terminals P and N in the two input terminal units 10 and 11. And the terminal R of the terminal unit 10 and the terminal O of the terminal unit 11 are connected to the power source 5a.

FIG. 5 corresponds to FIG.
This shows a case where 1 200 V is supplied to the inverter from the AC power supply 5b.
0, the AC power supply 5b is connected between the terminals R and S, and the terminal 1
The connection between terminal 1 O and AC power supply 5b is broken.

FIG. 6 is a perspective view of the outer shape of the inverter having the circuit configuration shown in FIG. 4 or FIG. 5, and the smoothing portion 21 constituted by the attached smoothing portion 3b and the input terminal portion 11 is shown in FIG. This is an example of a case in which the inverter unit 20 is disposed below the inverter unit 20 including components other than the smoothing unit, and is mounted without increasing the bottom area of the inverter unit 20 serving as a mounting surface of the inverter. Note that the smoothing section 21 becomes unnecessary as described above when the AC power supply has three phases.

[0018]

According to the present invention, a smoothing unit including a rectifying unit showing a three-phase full-wave rectifying circuit receiving an AC input, and a rectifying voltage smoothing capacitor connected in parallel to an output terminal of the rectifying unit. A general-purpose inverter comprising an inverter unit that outputs a required alternating current with the input rectified DC voltage as input, wherein the smoothing unit is configured by connecting two sets of capacitors of the same capacity in series, and a connection point between the two capacitors is provided. And three sets of terminals respectively drawn from the connection points between the upper and lower arms of each phase of the rectifier circuit, and a short-circuit piece for short-circuiting any two of the three sets of terminals. An input terminal for the AC input, or a series connection of a fixed capacitor for accommodating the smoothing unit inside the inverter and two sets of capacitors having the same capacity. Is separated into the accessory capacitor,
By providing two sets of input terminals as described above corresponding to the attached capacitor and the inverter, and making necessary connection changes in accordance with the voltage of the AC power supply and the number of phases at the two input terminals, the general-purpose power supply can be used. Inverter is single phase 100
V, single-phase 200V, and three-phase 200V can be commonly applied to three types of AC power supplies without changing the basic circuit configuration. The cost can be reduced, and when applied to the three-phase AC power supply, the size of the device can be reduced and the cost can be further reduced by removing the separate capacitor.

[Brief description of the drawings]

FIG. 1 is a circuit diagram of a three-phase inverter showing a first embodiment of the present invention.

FIG. 2 is an input terminal section connection change diagram corresponding to FIG. 1;

FIG. 3 is an explanatory diagram of a voltage doubler rectification operation at the time of single-phase AC input.

FIG. 4 is a circuit diagram (1φ100V) of a three-phase inverter showing a second embodiment of the present invention.

FIG. 5 is a circuit diagram (1φ200V) of a three-phase inverter showing a second embodiment of the present invention.

FIG. 6 is a perspective view of a three-phase inverter device according to a third embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Input terminal part 2 Rectification part 3 Smoothing part 3a Smoothing part 3b Attached smoothing part 4 Inverter part 5 AC power supply 5a AC power supply (1 100V) 5b AC power supply (1 200V) 5c AC power supply (3 200V) 6 AC motor 10 Input terminal part 11 Input terminal part C capacitor _{(C 1 ~C 3, C 41} ~C 43, C 51 ~C
₅₃₎ D diode (D ₁ ~D ₆₎

Claims (3)

(57) [Claims] 1. A rectifying unit forming a three-phase full-wave rectifier circuit receiving an AC input, a rectifying voltage smoothing capacitor connected in parallel to an output terminal of the rectifying unit, and a smoothing capacitor. A general-purpose inverter comprising: an inverter unit that receives a smoothed rectified DC voltage as an input and outputs a required AC; wherein the smoothing unit is configured by connecting two capacitors of the same capacity in series, and a connection between the two capacitors is provided. One set of terminals drawn from a point and three sets of terminals respectively drawn from the connection points between the upper and lower arms of each phase of the rectifier circuit in a bridge configuration and any two of the three sets of terminals are connected. A general-purpose inverter, comprising: an input terminal portion for the AC input having a short-circuit piece for short-circuiting. 2. A rectifying unit forming a three-phase full-wave rectifying circuit receiving an AC input, a smoothing unit including a rectifying voltage smoothing capacitor connected in parallel to an output terminal of the rectifying unit, and the smoothing capacitor. In a general-purpose inverter comprising an inverter unit which outputs a required AC with a smoothed rectified DC voltage as an input, three sets of terminals respectively drawn out from connection points between upper and lower arms of each phase of the rectifier circuit forming a bridge, and Providing an input terminal portion of the AC input having a short-circuiting piece for short-circuiting any two of the three terminals and two sets of terminals respectively drawn from the positive and negative bipolar buses on the output side of the rectifier circuit; In addition, the smoothing unit is formed by connecting two capacitors of the same capacity in series and connected in parallel with an attached capacitor provided separately from the inverter and a fixed capacitor housed inside the inverter. In addition, an input terminal portion having three sets of terminals respectively drawn from both ends of the series connection and an intermediate connection point with respect to the attached capacitor is provided, and the input terminal portion is separately provided from the inverter. A general-purpose inverter, wherein interconnection between a power supply and the attached capacitor is performed at the two input terminals according to the type of the AC power supply. 3. The general-purpose inverter according to claim 2, wherein
A general-purpose inverter wherein the attached capacitor and its input terminal are mounted on an appropriate surface such as a back surface thereof without increasing the required installation space of the inverter.