CN201966808U

CN201966808U - Variable frequency power source with three-gear voltage output

Info

Publication number: CN201966808U
Application number: CN2011200516799U
Authority: CN
Inventors: 李振虎; 岳贺; 赵金宝
Original assignee: SHANDONG WOCEN POWER SUPPLY EQUIPMENT CO Ltd
Current assignee: SHANDONG WOCEN POWER SUPPLY EQUIPMENT CO Ltd
Priority date: 2011-03-01
Filing date: 2011-03-01
Publication date: 2011-09-07
Anticipated expiration: 2021-03-01

Abstract

A variable frequency power source with three-gear voltage output belongs to the technical field of power supply devices, and comprises an isolation transformer, a transformer winding switching device and a logic control circuit. A primary winding W0 of the isolation transformer TR is connected with a power supply, secondary windings W1-W4 of the isolation transformer TR are connected with the transformer winding switching device, and the transformer winding switching device is connected with the logic control circuit. The isolation transformer is a single-phase transformer or a three-phase transformer, the transformer winding switching device is an alternating current contactor or a solid-state relay, and the logic control circuit is formed by logically combining a three-way switch and a relay. The variable frequency power source with three-gear voltage output has the advantage that by means of simple control logic and low cost, increasing of maximum output current of a variable frequency power source is conveniently realized.

Description

A kind of variable frequency power supply of third gear voltage output

Technical field

The utility model relates to a kind of variable frequency power supply of third gear voltage output, belongs to the power-supply device technical field.

Background technology

Variable frequency power supply in the market, its output voltage and electric current have following general character: output isolation transformer secondary is divided into two windings, use A.C. contactor or solid-state relay that above-mentioned two windings are carried out series-parallel operation, so that variable frequency power supply is when low-grade (i.e. two winding parallel connections), the twice when maximum output current is top grade (i.e. two windings in series).

In the laboratory of some colleges and universities or scientific research institution, particularly electromagnetism solidifies in the laboratory of industry, often can use a kind of variable frequency power supply, be used for providing the alternating current of adjustable voltage and adjustable frequency to a kind of load with following characteristics: when low-voltage and low frequency work, the electric current that flows through in the load is bigger; When high voltage and high-frequency operation, the electric current that flows through in the load is less.If select above-mentioned variable frequency power supply for use, though can satisfy instructions for use, the capacity of required variable frequency power supply is bigger, and price is higher.Under equal capacity requirement, the load that above-mentioned variable frequency power supply can drive is less, and this is the deficiencies in the prior art parts.

Summary of the invention

At the deficiencies in the prior art part, the utility model provides the variable frequency power supply of a kind of third gear voltage output, this variable frequency power supply can with the equal capacity of existing variable frequency power supply under, when output voltage is low, export bigger electric current.

A kind of variable frequency power supply of third gear voltage output, comprise isolating transformer, Transformer Winding switching device and logic control circuit, the elementary winding W0 of isolating transformer TR is connected with power supply, the secondary winding W1-W4 of isolating transformer TR is connected with the Transformer Winding switching device, and the Transformer Winding switching device is connected with logic control circuit.

Described isolating transformer is single-phase transformer or three-phase transformer.

Described Transformer Winding switching device is A.C. contactor or solid-state relay.

Described logic control circuit is for third gear switch and relay logic combine.

The each several part function is as follows:

Isolating transformer to the signal of inverter output isolate, transformation, this isolating transformer is secondary 4 windings.

The Transformer Winding switching device is by certain logical operation, and 4 secondary winding of isolating transformer are carried out series-parallel operation;

Logic control circuit produces the control signal of control transformer winding switching device work according to certain logic.

Being that single-phase transformer is an example below with the isolating transformer, is example with the A.C. contactor with the Transformer Winding switching device, sketches working condition of the present utility model:

Isolating transformer TR described in the utility model, it is secondary to be four winding W1-W4, and the maximum output voltage of each winding is Um/4, and wherein Um is the maximum output voltage of variable frequency power supply.

In use, by the setting to the different output voltage gears of variable frequency power supply, logic control circuit generates and produces different control signals, according to certain logic, the operating state of the coil L-KM1-L-KM3 of control KM1-KM3, and then reach the operating state of controlling A.C. contactor KM1-KM3.Combination according to KM1-KM3 different operating state, can carry out different serial or parallel connection operations to 4 secondary winding W1-W4 of isolating transformer TR, thereby the output voltage U o that makes variable frequency power supply is divided into three gear: 0-Um/4,0-Um/2,0-Um, and correspondingly the maximum output current of variable frequency power supply is followed successively by: 0-4Im, 0-2Im, 0-Im.The maximum output current of correspondence when wherein, Im is 0-Um for the variable frequency power supply output voltage range.

A kind of example that switches according to the Combination Control Transformer Winding of KM1-KM3 operating state is described below.Wherein, KM1-KM3 is the A.C. contactor of two normally opened contacts, one normally-closed contact.Low grade (L) at the variable frequency power supply output voltage, KM1-KM3 (the two normally opened contact closures of all switching on, one normally-closed contact disconnects), 4 secondary winding W1-W4 parallel connection of isolating transformer TR, because the maximum output voltage of each winding is Um/4, maximum output current is Im, so the output voltage range of variable frequency power supply is 0-Um/4, maximum output current is 4Im; Middle-grade (M) at the variable frequency power supply output voltage, KM1, KM2 (the two normally opened contact closures of switching on, one normally-closed contact disconnects), KM3 no power (two normally opened contacts disconnect, a normally-closed contact closure), W1 is in parallel with W2, W3 is in parallel with W4, connect after W1, the W2 parallel connection with after W3, the W4 parallel connection, the output voltage range of variable frequency power supply is 0-Um/2, and maximum output current is 2Im; At the top grade (H) of variable frequency power supply output voltage, the equal no power of KM1-KM3 (two normally opened contacts disconnect, a normally-closed contact closure), W1-W4 all connects, and the output voltage range of variable frequency power supply is 0-Um, and maximum output current is Im.

Compared with prior art, advantage and positive effect that the utility model had are: the utility model with lower cost, has been realized the lifting of variable frequency power supply maximum output current by simple control logic easily.

Description of drawings

Fig. 1 is a theory diagram of the present utility model.

Fig. 2 is the electrical schematic diagram that isolating transformer is connected with the Transformer Winding switching device.

Fig. 3 is the circuit theory diagrams of logic control circuit.

Wherein: 1, logic control circuit, 2, Transformer Winding switching device, TR, isolating transformer, the elementary winding of W0, isolating transformer, 4 secondary winding of W1--W4, isolating transformer, Uo is the output of variable frequency power supply, KM1-KM3, be the A.C. contactor of a normally-closed contact of two normally opened contacts, SW, third gear diverter switch, are relay at K1-K3, L-KM1-L-KM3, are the coil of A.C. contactor KM1-KM3.

Embodiment

The utility model is described in further detail below in conjunction with drawings and Examples.

Embodiment 1:

A kind of variable frequency power supply of third gear voltage output, as Fig. 1, Fig. 2 and shown in Figure 3, comprise isolating transformer, Transformer Winding switching device (2) and logic control circuit (1), the elementary winding W0 of isolating transformer TR is connected with power supply, the secondary winding W1-W4 of isolating transformer TR is connected with Transformer Winding switching device (2), and Transformer Winding switching device (2) is connected with logic control circuit (1).

Described isolating transformer TR is a single-phase transformer.

Described Transformer Winding switching device (2) is an A.C. contactor.

Described logic control circuit is that third gear switch and relay logic combine, its circuit theory diagrams such as accompanying drawing 3.)

Embodiment 2:

A kind of variable frequency power supply of third gear voltage output, circuit structure is identical with embodiment 1, and difference is:

Described isolating transformer TR is a three-phase transformer.

Described Transformer Winding switching device (2) is a solid-state relay.

Claims

1. the variable frequency power supply of third gear voltage output, it is characterized in that, comprise isolating transformer, Transformer Winding switching device and logic control circuit, the elementary winding W0 of isolating transformer TR is connected with power supply, the secondary winding W1-W4 of isolating transformer TR is connected with the Transformer Winding switching device, and the Transformer Winding switching device is connected with logic control circuit.

2. the variable frequency power supply of a kind of third gear voltage output as claimed in claim 1 is characterized in that described isolating transformer is single-phase transformer or three-phase transformer.

3. the variable frequency power supply of a kind of third gear voltage output as claimed in claim 1 is characterized in that described Transformer Winding switching device is A.C. contactor or solid-state relay.

4. the variable frequency power supply of a kind of third gear voltage output as claimed in claim 1 is characterized in that described logic control circuit is that third gear switch and relay logic combine.