KR101390312B1 - H-bridge converter system - Google Patents

Abstract

An H-bridge converter system is disclosed. H-bridge converter system of the present invention is a master controller for outputting a plurality of first control signals for controlling the operation of the motor or generator, each of a plurality of power cells in accordance with the first control signal A plurality of power cell controllers controlling a plurality of power cell controllers, and a communication interface unit performing synchronous serial communication between the master controller and the power cell controllers, the communication interface unit transmitting to each power cell controller. The signal is synchronized by the power cell selection signal, and the serial communication follows the Serial Peripheral Interconnect (SPI) communication protocol for peripheral devices. This improves the communication speed.

Description

H-bridge converter system {H-BRIDGE CONVERTER SYSTEM}

The present invention relates to an H-bridge converter system for controlling the phase of a power cell. More particularly, the controller of the system includes a master controller and a power cell controller, and synchronous serial communication between the master controller and the power cell controller. It relates to an H-bridge converter system for communicating data using a.

In general, each phase of an advanced regenerative H-bridge converter system is composed of several cells connected in series.

The advanced regenerative H-bridge converter includes a power supply unit, a transformer unit, a power cell stack unit, and an electric motor. The power supply unit supplies power for driving the motor to the transformer unit.

The transformer section has several tabs on the secondary side in a zigzag or extended delta connection method. The transformer supplies independent power to each power cell and forms a multi-pulse rectifier type converter with a phase difference between the secondary side taps. Thus, the input stage THD (Total) is much lower than the conventional 6-pulse rectification method. Harmonic Distortion).

Each stack of power cell stacks has an independent single-phase converter structure, and has an advanced regenerative cell structure. The advanced regenerative cell is used to return the regenerative energy to the power supply in case of a load requiring rapid acceleration and deceleration. To this end, the input converter unit is configured as a three-phase single pulse width modulation (PWM) converter using an insulated gate bipolar transistor (IGBT). A reactor for current control is connected to the converter, and a noise filter for preventing EMI (Electromagnetic interference) noise from switching into the power system is attached.In contrast to the basic economy type, the input transformer has a phase-controlled PWM converter in the input unit. Therefore, there is no phase difference between the secondary sides of the transformer.

Compared with the general multi-level converter, the cascaded H-bridge converter can easily change the voltage level by adjusting the number of cells, and can be repaired by unit replacement in case of failure. It is easy to use, and it is advantageous power topology because it is possible to implement more reliable and flexible failure monitoring and diagnosis function by separating into failure monitoring function by cell unit and failure monitoring function by system unit.

If the power topology is an H-bridge converter, the controller can be configured in two ways: centralized control and distributed control.

In the distributed control method, an auxiliary controller is installed in each cell to generate a gating signal or to perform cell-based protection. Therefore, since only data exchange such as a voltage / current reference value and a fault signal is performed between the cell and the main controller, the signal line is simple and the burden on the main controller is reduced. In addition, since the protection operation of the cell unit is easy, it is possible to increase the reliability of the entire system and advantageous structure in terms of modularization.

Looking at the distributed control method used in the prior art in detail, the desired control command value from the console (Console) to receive the RS-232C serial communication that is mounted on the controller, the communication frame (Frame) to send it to the cell controller (Cell Controller) After configuration, it converts into duty cycle defined using single phase pulse width modulation (PWM) logic in EPLD and transmits it to cell controller through optical connector.

When the controller is configured in a distributed control scheme and the power cell uses an advanced regenerative structure using a PWM converter, it is difficult to increase the switching frequency because the amount of data to be transmitted and received between the main controller and the power cell controller increases.

It is an object of the present invention to provide an H-bridge converter system capable of high speed communication using a synchronous communication method.

H-bridge converter system according to an embodiment of the present invention for achieving the technical problem is a master controller for outputting a plurality of first control signals for controlling the operation of the motor or generator; A plurality of power cell controllers controlling each of a plurality of power cells according to the first control signal; And a communication interface configured to perform synchronous serial communication between the master controller and the power cell controllers.

Signals transmitted by the communication interface unit to each power cell controller are synchronized by a power cell selection signal, and the serial communication follows a serial peripheral interconnect (SPI) communication protocol for peripheral devices.

The communication interface unit may further include an erasable programmable logic device (EPLD) for converting the plurality of first control signals into a plurality of second control signals for transmission to the plurality of power cell controllers, respectively.

The communication interface unit may simultaneously transmit data to each of the power cell controllers and simultaneously receive data from each of the power cell controllers.

The power cell may include a plurality of pulse width modulation (PWM) converters.

Each of the power cell controllers converts the second control signal into a pulse width modulation (PWM) control signal and transmits it to each of the power cells. You can sense it.

The H-bridge converter system according to the present invention can implement high-speed communication by using a synchronous communication method, which is more suitable for the H-bridge converter system having power generation and regenerative functions.

1 is a block diagram showing the optical communication structure of the H-bridge converter system according to an embodiment of the present invention.
FIG. 2 is a diagram illustrating in detail the internal signal of the power cell of FIG. 1 according to the first embodiment of the present invention.
3 is a timing diagram of a plurality of second control signals according to the first embodiment of the present invention.
4 is a timing diagram of a plurality of second control signals according to a second embodiment of the present invention.

Specific structural and functional descriptions of embodiments according to the concepts of the present invention disclosed in this specification or application are merely illustrative for the purpose of illustrating embodiments in accordance with the concepts of the present invention, The examples may be embodied in various forms and should not be construed as limited to the embodiments set forth herein or in the application.

Embodiments in accordance with the concepts of the present invention can make various changes and have various forms, so that specific embodiments are illustrated in the drawings and described in detail in this specification or application. It should be understood, however, that it is not intended to limit the embodiments according to the concepts of the present invention to specific forms of disclosure, but includes all modifications, equivalents, and alternatives falling within the spirit and scope of the present invention.

Terms such as first and / or second may be used to describe various components, but the components should not be limited by the terms. The terms are intended to distinguish one element from another, for example, without departing from the scope of the invention in accordance with the concepts of the present invention, the first element may be termed the second element, The second component may also be referred to as a first component.

When a component is referred to as being "connected" or "connected" to another component, it may be directly connected to or connected to that other component, but it may be understood that other components may be present in between. Should be. On the other hand, when an element is referred to as being "directly connected" or "directly connected" to another element, it should be understood that there are no other elements in between. Other expressions that describe the relationship between components, such as "between" and "between" or "neighboring to" and "directly adjacent to" should be interpreted as well.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this specification, the terms "comprises ", or" having ", or the like, specify that there is a stated feature, number, step, operation, , Steps, operations, components, parts, or combinations thereof, as a matter of principle.

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Terms such as those defined in the commonly used dictionaries should be construed as having meanings consistent with the meanings in the context of the related art, and are not construed in ideal or excessively formal meanings unless expressly defined herein. Do not.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail with reference to the preferred embodiments of the present invention with reference to the accompanying drawings.

1 is a block diagram showing the optical communication structure of the H-bridge converter system according to an embodiment of the present invention. FIG. 2 is a diagram illustrating in detail the internal signal of the power cell of FIG. 1 according to the first embodiment of the present invention.

Referring to FIGS. 1 and 2, the H-bridge converter system 200 according to the present invention includes a plurality of power cells 230 including a master controller 210 and a power cell controller 231, respectively. ). A communication interface 220 is provided between the master controller 210 and the plurality of power cell controllers 231 to perform data communication such as a voltage reference value and a failure signal by serial communication. Hereinafter, an electric motor will be described as an example, but the present invention is also applicable to a generator.

The master controller 210 has a variable speed controller for controlling the acceleration and the shift of the electric motor, and calculates a voltage value and a current value required for the motor. It also performs the monitoring, diagnostic and protection functions of the entire converter system, as well as man-machine interface (MMI), communication with the power cells and other auxiliary functions.

The master controller 210 outputs a plurality of first control signals for controlling the operation of the motor to the power cell controller 231 through the communication interface 220. The plurality of first control signals are included in the SPI Com signal. The plurality of first control signals may include a voltage reference value, a PWM sync signal, a reactive power reference value, and a DC link reference value.

The PWM sync signal is used to transmit the voltage reference value of the three phases, which are outputs of the variable speed controller, to the power cell controller 231 in synchronization with each phase.

Meanwhile, the master controller 210 may receive information about a cell state of each cell from the power cell controller 231 through the communication interface 220.

The communication interface 220 performs synchronous serial communication between the master controller 210 and the power cell controller 231. Serial communication may follow the Serial Peripheral Interconnect (SPI) communication protocol.

The communication interface 220 converts a plurality of first control signals into a plurality of second control signals 240 respectively transmitted to the plurality of power cell controllers 231, and an erasable programmable logic device (EPLD) 221. It may include. The plurality of second control signals 240 corresponding to the respective power cell controllers 231 are respectively controlled by the controllers 221-1, 221-2,..., 221-9 included in the EPLD 221. Since processed in logic, the communication interface 220 can simultaneously transmit data to each of the power cell controllers 231 and receive data from each of the power cell controllers at the same time. The number of each of the controllers 221-1, 221-2,..., 221-9 may be the same as the number of the power cell controllers 231.

The plurality of second control signals include a power cell select signal (nCS), a clock (CLK), a master output slave input (MOSI), and a master input slave output (MISO) signal. The nCS signal, the MOSI, and the MISO signal transmitted to each power cell may be the same or different according to the EPLD 221 implementation scheme of the communication interface 220. The communication interface 220 is connected to each of the power cells by four signal lines, and transmits and receives a plurality of second control signals. This will be described in more detail with reference to FIG. 4.

The communication interface unit 220 may include an optical communication device capable of SPI communication. The optical communication device may transmit a direct current (DC) signal and transmit a power cell selection signal included in the plurality of second control signals.

Each power cell 230 may be classified into three groups G1, G2, and G3, and the power cells of each group are connected in series to each phase S1, S2, and S3 of the H-bridge converter system. ) In the drawings, three power cells are included in each group, but the present invention is not limited thereto.

The power cell controller 231 is located for each power cell 230, and controls each of the plurality of power cells according to the first control signal of the master controller 210. The power cell may include a plurality of pulse width modulation (PWM) converters having an input converter unit.

Each power cell controller 231 converts the second control signal into a pulse width modulation (PWM) control signal and transmits it to the stack 233 of each power cell to drive the power cell 230.

The power cell controller 231 may input and confirm cell position information and abnormality / absence using a keypad and a display device.

In addition, the power cell controller 231 may sense voltage, current, fault, and stack temperature of each power cell for system protection and PWM control, and a bypass switch in case of power cell failure. By operating the controller, the system can be operated without stopping even in the event of a power cell failure.

The master controller 210 may include a high function digital signal processing (DSP) and peripheral circuits, and the power cell controller 231 may include a one-chip DSP including peripheral circuit functions.

The EPLD 221 of the communication interface 220 may be configured to include only one control unit 221-1. The plurality of second control signals may be processed in logic by the controller 221-1.

3 is a timing diagram of a plurality of second control signals according to the first embodiment of the present invention. 4 is a timing diagram of a plurality of second control signals according to the second embodiment of the present invention.

3 and 4, first, each power cell is selected using a plurality of nCS signals. The nCS signal is composed of / CS # 1 to / CS # n signals transmitted to each of n power cells. At this time, the nCS signal transmitted to each power cell is controlled according to the PWM sync signal transmitted from the master controller 210 to the communication interface unit 220, thereby synchronizing the PWM signals driving the respective power cells.

When the nCS signal is 0, a corresponding power cell is selected to transmit data in synchronization with the clock signal CLK. A signal is transmitted from a master controller to each power cell controller through a MOSI signal line, and a signal is transmitted from each power cell controller to a master controller through a MISO signal line. In the drawings, an embodiment in which the MOSI signal and the MISO signal are sequentially transmitted is illustrated, but is not limited thereto. That is, the MOSI signal and the MISO signal may be transmitted at the same time.

Data is transmitted bit by bit in accordance with the clock, and is shown in units of 8 bits, but may be implemented in units of 12 bits, 16 bits, or more. The transmission of data may begin with the MSB or may begin with the LSB.

In a power cell having an nCS signal of 1, the MISO signal line is maintained at a high impedance (HIZ), and data transmission and reception are not performed.

As shown in FIG. 3, the plurality of power cell selection signals may be zero at the same time, and data transmission and reception may be performed with the plurality of power cells. At this time, since the EPLD 221 of the communication interface 220 includes a plurality of controllers 221-1, 221-2,..., 221-9 corresponding to each power cell, transmission from each power cell. The MISO # 1 to MISO # n signals and the MOSI # 1 to MOSI # n signals transmitted to the respective power cells do not collide with each other, and the respective controllers 221-1, 221-2, ..., 221-9 Can be processed in

However, as shown in FIG. 4, the plurality of power cell selection signals may be sequentially 0 to exchange data. In this case, the EPLD 221 of the communication interface 220 may include only one controller 221-1 corresponding to the entire power cell.

While the present invention has been described with reference to exemplary embodiments thereof, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the scope of the present invention. Accordingly, the true scope of the present invention should be determined by the technical idea of the appended claims.

110: power supply unit 120: transformer
130: power cell stack 140: electric motor
200: H-bridge converter system of the present invention
210: master controller 220: communication interface unit
221: EPLD 221-1 to 221-9: control unit
230: power cell 231: power cell controller
233: power cell stack 240: second control signal
nCS: Power cell select signal CLK: Clock

Claims (7)

A master controller for outputting a plurality of first control signals for controlling an operation of an electric motor or a generator;
A plurality of power cell controllers controlling each of a plurality of power cells according to the first control signal; And
A communication interface configured to perform synchronous serial communication between the master controller and the power cell controllers,
The signal transmitted to the respective power cell controllers by the communication interface is synchronized with the power cell selection signal,
The serial communication is in accordance with the Serial Peripheral Interconnect (SPI) communication protocol,
The communication interface unit
Connected to each of the power cell controllers by at least four signal lines,
The power cell selection signals transmitted from the communication interface unit to the plurality of power cell controllers are the same,
The communication interface unit
And selecting the plurality of power cells simultaneously using the power cell selection signal and performing SPI communication with the selected plurality of power cells. The method of claim 1, wherein the communication interface unit
And an erasable programmable logic device (EPLD) for converting the plurality of first control signals into a plurality of second control signals for transmission to the plurality of power cell controllers, respectively. The method of claim 2, wherein the communication interface unit
And simultaneously transmit data to the respective power cell controllers and simultaneously receive data from the respective power cell controllers. The method of claim 2, wherein the power cell
An H-bridge converter system comprising a plurality of Pulse Width Modulation (PWM) converters. The method of claim 4, wherein each power cell controller is
H-bridge converter converts the second control signal into a pulse width modulation (PWM) control signal and transmits it to each of the power cells, and senses a voltage, a current, a fault, and a stack temperature of each of the power cells. system. delete delete

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