CN201674405U

CN201674405U - High voltage frequency converter with four-quadrant operation function

Info

Publication number: CN201674405U
Application number: CN2010201814339U
Authority: CN
Inventors: 孙开发; 石磊
Original assignee: GUANGZHOU ZHIGUANG ELECTRIC CO Ltd
Current assignee: GUANGZHOU ZHIGUANG ELECTRIC CO Ltd
Priority date: 2010-05-06
Filing date: 2010-05-06
Publication date: 2010-12-15
Anticipated expiration: 2020-05-06

Abstract

The utility model discloses a high voltage frequency converter with four-quadrant operation function, comprising a three-phase phase-shifting transformer and a plurality of power units, which are sequentially connected, and also comprising a main control system connected with all the power units, wherein the primary side of the three-phase phase-shifting transformer is installed with a voltage transformer or added with an auxiliary winding; the output of the voltage transformer or the auxiliary winding is connected with the primary side of an isolation transformer; and at least one isolation transformer is arranged between the voltage transformer or auxiliary winding and each power unit. The frequency converter omits the alternating current reactor at the input side of the power unit, ensures the system to obtain good control effect, and has remarkable effects on optimizing cost and reducing volume and weight.

Description

High voltage converter with four quadrant running function

Technical field

The utility model relates to a kind of power unit cascade type high voltage frequency changer with four quadrant running function.

Background technology

Under the guiding of power price rise and energy-saving and emission-reduction macro policy, along with the fast development of power electronic technology, in the huge industry of energy consumptions such as electric power, metallurgy and petrochemical industry, high voltage converter has been obtained widely and has been used.

Fig. 1 is the structure of existing power unit cascade type high voltage frequency changer, and its main circuit mainly comprises phase shifting transformer 1 and a plurality of power cell 2.In numerous high-pressure frequency-conversion schemes, adopt that the high voltage converter of this scheme has that the voltage fan-out capability is strong, the sinusoidal degree height of output voltage, advantage such as little and dv/dt is very little to the pollution of electrical network, become one of main flow scheme of present high voltage converter.

In commercial Application, a lot of occasions require high voltage converters must possess the ability of four quadrant running, that is to say that electric energy both can flow to motor by electrical network, also can be by the electromotor feedback net of wiring back.Under this topological structure of power unit cascade, require each power cell to adopt full control power cell, its rectifier bridge is made of all-controlling power electronics device (for example IGBT), as shown in Figure 2.In addition, rectifier bridge work the time need be obtained accurately input voltage phase of power unit with control input side electric current.

Common way is between phase shifting transformer secondary winding and power cell input AC reactor to be installed, so that the output voltage of phase shifting transformer secondary winding is carried out phase-detection; Yet phase shifting transformer secondary winding number is more, and each power cell is all installed the volume and weight that AC reactor will increase high voltage converter significantly, brings adverse effect for the installation and the cost of high voltage converter.

The utility model content

The purpose of this utility model is effectively to reduce the volume and weight of the high voltage converter with four quadrant running function, and a kind of high voltage converter power cell input side AC reactor, that have the four quadrant running function that need not is provided.

The purpose of this utility model is achieved through the following technical solutions: have the high voltage converter of four quadrant running function, comprise the three-phase phase-shifting transformer, the some power cells that connect successively, also comprise the master control system that is connected with each power cell; The former limit of three-phase phase-shifting transformer is installed voltage transformer or is set up auxiliary winding, and the output of voltage transformer or auxiliary winding links to each other with the former limit of isolating transformer; Be provided with at least one isolating transformer between voltage transformer or auxiliary winding and each power cell.

Many secondary winding transformer that described isolating transformer is one or more mutual isolation, or single secondary winding transformer of a plurality of mutual isolation are filled dielectric isolation layer between the former limit winding of isolating transformer and lead-out wire and secondary winding and the lead-out wire.

Described power cell comprises voltage-phase testing circuit, the controller that is connected; The controller of described master control system and each power cell links to each other by optical fiber; The secondary of described isolating transformer is connected to the voltage-phase testing circuit in each power cell.

Described voltage-phase testing circuit comprises circuit of synchronous rectification, zero passage comparison circuit, the phase-locked loop circuit that connects successively.

The utility model has following advantage and effect with respect to prior art: make the high voltage converter with four quadrant running function can cancel the AC reactor of power cell input side, and the assurance system can obtain good control effect, optimize cost for high voltage converter, reduced volume and weight reduction have remarkable effect.

Description of drawings

Fig. 1 is the topology diagram of existing power unit cascade type high voltage frequency changer main circuit;

Fig. 2 is the topology diagram of existing full control power cell main circuit;

Fig. 3 is the topology diagram that the utlity model has the high voltage converter of four quadrant running function;

Fig. 4 is the schematic diagram of detection power unit input voltage phase.

Embodiment

Below in conjunction with embodiment and accompanying drawing the utility model is described in further detail, but execution mode of the present utility model is not limited thereto.

Embodiment

Shown in Figure 3, the high voltage converter that the utlity model has the four quadrant running function comprises three-phase phase-shifting transformer 1, some power cells 2, master control system 3, at least one isolating transformer 6; Voltage transformer 5 or auxiliary winding are installed in the former limit of three-phase phase-shifting transformer 1.With the former limit of three-phase phase-shifting transformer 1 voltage transformer 5 being installed below is example, and most preferred embodiment of the present utility model is done detailed description:

The former limit winding of three-phase phase-shifting transformer 1 passes through high-voltage switch gear or directly links to each other with three phase network, and the direct inputs with some power cells 2 of each winding of secondary connect one to one.Comprise the voltage-phase testing circuit, the controller that are connected in the power cell 2; Link to each other with motor load behind the power unit cascade of homophase.Link to each other by optical fiber 4 between the controller of master control system 3 and each power cell 2, by the control signal of Optical Fiber Transmission master control system and the feedback signal of power cell.Voltage transformer 5 is installed in the former limit of three-phase phase-shifting transformer, the output of voltage transformer links to each other with the former limit of isolating transformer 6, the secondary of isolating transformer is connected to the voltage-phase testing circuit in each power cell, the phase signal of voltage-phase testing circuit output directly is sent to the controller of power cell, and controller draws the phase place of power cell input voltage according to the electrical degree phase difference calculating of the voltage-phase on the former limit of phase shifting transformer and the former and deputy polygonal voltage phase place of phase shifting transformer.In the control algolithm (as vector control) of the controller of power cell with the phase place substitution power cell rectifier bridge of power cell input voltage, the input current of power controlling unit and dc voltage; According to the control signal of the master control system of optical fiber input, the frequency and the amplitude of power controlling unit output voltage.Owing to adopted said structure, the utility model to need not between phase shifting transformer secondary winding and power cell input, AC reactor to be installed.

The utility model employing method of integrated voltage-phase testing circuit in power cell solves the problem of detection power unit input voltage phase; The principle that detects as shown in Figure 4, detailed process is as follows: voltage measuring transformer obtains the input voltage of high voltage converter, is transported to voltage-phase testing circuit in each power cell through isolating transformer then.In the present embodiment, described voltage-phase testing circuit comprises circuit of synchronous rectification, zero passage comparison circuit, the phase-locked loop circuit that connects successively, the course of work of voltage-phase testing circuit is: circuit of synchronous rectification carries out rectification to the low pressure sinusoidal signal of input, output has only the voltage waveform of positive half wave, the square-wave signal of output and line voltage same phase is to phase-locked loop circuit behind the process zero passage comparison circuit again, and phase-locked loop circuit utilizes closed circuit that the inhibitory action of error is obtained the output waveform consistent with the input signal phase place.

Phase shifting transformer is a kind of special transformer that is applied to unit cascade type high voltage frequency changer, it is made of single former limit winding and many secondary winding, effectively reduces the harmonic wave injection of high voltage converter to electrical network by the certain electrical degree of phase shifting that makes a plurality of secondary winding output voltages.The voltage-phase angle difference on the former and deputy limit of phase shifting transformer is determined according to designing requirement in theory, but because the dispersiveness on the manufacturing process, the voltage-phase angle missionary society and the designing requirement of the former and deputy limit of phase shifting transformer winding reality have fine distinction.So the voltage-phase angle difference on the former and deputy limit of phase shifting transformer must be measured in the no load test of phase shifting transformer, as setting the controller of input power unit (or master control system) in advance, perhaps under the high voltage converter Light Condition, measure the controller (or master control system) of on-the-spot input power unit by power cell.

In the present embodiment, isolating transformer preferably adopts the high withstand voltage transformer of isolating, fill dielectric isolation layer between its former limit winding and lead-out wire and secondary winding and the lead-out wire, can guarantee the high voltage converter primary circuit and the power cell secondary circuit between insulation reliable.According to the number difference of secondary winding, the isolating transformer that is adopted can be selected many secondary winding transformer of one or more high withstand voltage mutual isolation for use, also can be single secondary winding transformer of a plurality of high withstand voltage mutual isolation.The concrete grammar of voltage-phase testing circuit locking input voltage phase is not to have only the synchronous rectification phase-locked loop a kind of yet.Except voltage transformer, also can measure the high voltage converter input voltage by the way of on phase shifting transformer, setting up auxiliary winding, the output of auxiliary winding links to each other with the former limit of isolating transformer.All are based on the utility model, adopt technically voltage transformer (perhaps auxiliary winding) measure input voltage, through isolating transformer transmit, in power cell, carry out phase-detection design all within protection range.

The foregoing description is the utility model preferred implementation; but execution mode of the present utility model is not restricted to the described embodiments; other any do not deviate from change, the modification done under spirit of the present utility model and the principle, substitutes, combination, simplify; all should be the substitute mode of equivalence, be included within the protection range of the present utility model.

Claims

1. the power unit cascade type high voltage frequency changer that has the four quadrant running function comprises the three-phase phase-shifting transformer, the some power cells that connect successively, also comprises the master control system that is connected with each power cell; It is characterized in that: the former limit of three-phase phase-shifting transformer is installed voltage transformer or is set up auxiliary winding, and the output of voltage transformer or auxiliary winding links to each other with the former limit of isolating transformer; Be provided with at least one isolating transformer between voltage transformer or auxiliary winding and each power cell.

2. the high voltage converter with four quadrant running function according to claim 1, it is characterized in that: many secondary winding transformer that described isolating transformer is one or more mutual isolation, or single secondary winding transformer of a plurality of mutual isolation, fill insulating barrier between the former limit winding of isolating transformer and lead-out wire and secondary winding and the lead-out wire.

3. the high voltage converter with four quadrant running function according to claim 1 is characterized in that: described power cell comprises voltage-phase testing circuit, the controller that is connected; The controller of described master control system and each power cell links to each other by optical fiber; The secondary of described isolating transformer is connected to the voltage-phase testing circuit in each power cell.

4. the high voltage converter with four quadrant running function according to claim 3 is characterized in that: described voltage-phase testing circuit comprises circuit of synchronous rectification, zero passage comparison circuit, the phase-locked loop circuit that connects successively.