Circuit and equipment for starting energy-consuming brake of four-quadrant frequency converter by using single-phase power supply

Abstract

The utility model relates to a frequency converter technology, and discloses a circuit and equipment for starting energy-consuming braking of a four-quadrant frequency converter by using a single-phase power supply. The utility model provides a circuit for starting energy-consuming braking of a four-quadrant frequency converter by using a single-phase power supply. The circuit comprises the four-quadrant frequency converter, an external power supply, the single-phase power supply, an energy-consuming device and a motor, the four-quadrant frequency converter comprises a controllable rectification feedback unit and an inversion unit, and the controllable rectification feedback unit and the inversion unit are connected in parallel through a direct current bus; the single-phase power supply is connected with any two of R, S and T three-phase interfaces of the controllable rectified feedback unit, and unconnected phase interfaces are configured as additional phase interfaces; the energy consumption device comprises a control element and an energy consumption resistor, one end of the energy consumption device is connected with the additional phase interface, and the other end of the energy consumption device is connected with any terminal of the direct current bus. The power consumption function of a four-quadrant frequency converter power generation mode can be realized, and system modification and system cost are reduced.

Description

Technical Field

[0001] The utility model relates to the field of frequency converters, and particularly to a circuit and a device for starting energy-consuming braking of a four-quadrant frequency converter by using a single-phase power supply. Background Technique

[0002] An elevator is a device for converting electrical energy and gravitational potential energy, that is, there is an operation mode of converting electrical energy into gravitational potential energy (electric mode), and there is also a mode of converting gravitational potential energy into electrical energy (power generation mode). In the power generation mode, the four-quadrant frequency converter feeds back the electrical energy generated by the elevator to the power grid for reuse through the front-end rectifier feedback unit. With the demand for energy conservation and emission reduction, the traditional two-quadrant frequency converter's solution of consuming electrical energy in the power generation mode by heating the braking resistor cannot meet the requirements, and the demand for four-quadrant frequency converters is increasing.

[0003] In elevator applications, in addition to the normal power grid power supply working mode, there is also a power failure rescue mode. In the power failure backup power supply rescue mode, the elevator will also work in the power generation mode. This requires that the backup rescue power supply supports the energy absorption and consumption function of the frequency converter feedback, or the four-quadrant frequency converter integrates the energy consumption function again. If the backup power supply supports the absorption of feedback energy, the backup power supply must use a three-phase power supply, and the output side of the backup power supply must be a bidirectional inverter, and at the same time, an electric energy consumption unit must also be integrated. Such a backup rescue power supply will have disadvantages such as high cost, large development difficulty, and large volume. Content of the Utility Model

[0004] The purpose of the utility model is to provide a circuit and a device for starting energy-consuming braking of a four-quadrant frequency converter by using a single-phase power supply, which are used to realize the energy consumption of the elevator power generation mode through a four-quadrant frequency converter and an externally added energy-consuming braking resistor without changing the design of the frequency converter and while still using a common single-phase backup rescue power supply.

[0005] To solve the above technical problems, an embodiment of the utility model provides a circuit for starting energy-consuming braking of a four-quadrant frequency converter by using a single-phase power supply, including:

[0006] A four-quadrant frequency converter, an external power supply, a single-phase power supply, an energy-consuming device, and a motor;

[0007] The four-quadrant frequency converter includes a controllable rectifier feedback unit and an inverter unit, and the controllable rectifier feedback unit and the inverter unit are connected in parallel through a DC bus;

[0008] The external power supply is connected to the R, S, and T three-phase interfaces of the controllable rectifier feedback unit;

[0009] The single-phase power supply is connected to any two of the R, S, and T three-phase interfaces of the controllable rectifier feedback unit, and the unconnected phase interface is configured as an additional phase interface;

[0010] The energy-consuming device includes a control element and an energy-consuming resistor. One end of the energy-consuming device is connected to the additional phase interface, and the other end of the energy-consuming device is connected to any terminal of the DC bus;

[0011] The motor is connected to the inverter unit;

[0012] When the external power supply is powered on, the single-phase power supply and the energy-consuming device are both disconnected from the four-quadrant frequency converter;

[0013] When the external power supply is disconnected, the single-phase power supply and the energy-consuming device are both connected to the four-quadrant frequency converter.

[0014] In addition, the controllable rectifier feedback unit includes 6 insulated gate bipolar transistors;

[0015] When the single-phase power supply supplies power to the motor, the additional phase interface, the energy-consuming device and the target insulated gate bipolar transistor in the controllable rectifier feedback unit are connected in parallel to the DC bus, so that the single-phase power supply cannot drive the controllable rectifier feedback unit, but can drive the inverter unit to control the motor;

[0016] When the motor supplies power to the single-phase power supply, the voltage of the DC bus rises, the on-off of the target insulated gate bipolar transistor is controlled, and the energy-consuming device is used to consume the power of the DC bus, so that the power generated by the motor can be consumed by the energy-consuming device.

[0017] In addition, the control element is a sectional contactor, a controllable sectional semiconductor or a power relay.

[0018] In addition, the on-off of the control element is controlled by the single-phase power supply.

[0019] In addition, the on-off of the control element is controlled by the four-quadrant frequency converter.

[0020] In addition, the external power supply is a three-phase power supply network.

[0021] In addition, the single-phase power supply is inverted to output alternating current or direct current after being boosted by a battery.

[0022] In addition, the motor is a three-phase motor.

[0023] In addition, the energy-consuming device is used as a fast discharge circuit for the DC bus.

[0024] An embodiment of the present invention further provides a device, and the device is an electronic device including the circuit for starting the four-quadrant frequency converter with energy consumption braking by using a single-phase power supply.

[0025] Compared with the prior art, in the embodiment of the present utility model, through the connection mode of an energy-consuming device, when the external power supply of the four-quadrant frequency converter is powered off, without changing the structure of the four-quadrant frequency converter, the controllable rectifier feedback unit can be disabled, and the elevator power generation is consumed through the energy-consuming resistor, so as to realize the availability of the single-phase backup power supply. Therefore, the solution described in the present utility model, without changing the design of the frequency converter, while using the common single-phase backup rescue power supply, realizes the energy consumption of the elevator power generation mode through the four-quadrant frequency converter and the externally added energy-consuming brake resistor. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] One or more embodiments are exemplarily illustrated by the pictures in the corresponding drawings. These exemplary illustrations do not constitute a limitation on the embodiments. Elements with the same reference numerals in the drawings are represented as similar elements. Unless otherwise stated, the drawings in the drawings do not constitute a scale limitation.

[0027] Figure 1 It is a schematic circuit diagram of using a single-phase power supply to start the energy-consuming braking of a four-quadrant frequency converter according to an embodiment of the present utility model.

[0028] The realization of the purpose, functional features and advantages of the present utility model will be further described with reference to the embodiments and the drawings. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0029] To make the purposes, technical solutions and advantages of the embodiments of the present utility model clearer, the embodiments of the present utility model will be described in detail below with reference to the drawings. However, those skilled in the art can understand that in the embodiments of the present utility model, many technical details are proposed for the convenience of readers to understand the present application. However, even without these technical details and various changes and modifications based on the following embodiments, the technical solutions required to be protected by the present application can be realized. The division of the following embodiments is for the convenience of description and should not constitute any limitation on the specific implementation manner of the present utility model. The various embodiments can be combined and cited with each other on the premise of not contradicting each other.

[0030] An embodiment of the present utility model relates to a circuit for using a single-phase power supply to start the energy-consuming braking of a four-quadrant frequency converter. The schematic diagram of the circuit for using a single-phase power supply to start the energy-consuming braking of the four-quadrant frequency converter is as Figure 1 shown and includes:

[0031] A four-quadrant frequency converter, an external power supply, a single-phase power supply, an energy-consuming device and a motor.

[0032] Among them, the four-quadrant inverter includes a controllable rectifier feedback unit and an inverter unit, and the controllable rectifier feedback unit and the inverter unit are connected in parallel through a DC bus; the external power supply is connected to the R, S and T three-phase interfaces of the controlled rectifier feedback unit; the single-phase power supply is connected to any two of the R, S and T three-phase interfaces of the controlled rectifier feedback unit, and the unconnected phase interface is configured as an additional phase interface; the energy consumption device includes a control element and an energy consumption resistor, one end of the energy consumption device is connected to the additional phase interface, and the other end of the energy consumption device is connected to any terminal of the DC bus; the motor is connected to the inverter unit.

[0033] During the operation of the circuit of the utility model, when the external power supply has power, the single-phase power supply and the energy consumption device are disconnected from the four-quadrant frequency converter; when the external power supply is disconnected, the single-phase power supply and the energy consumption device are connected to the four-quadrant frequency converter.

[0034] refer to Figure 1 As shown, in the embodiment of the utility model, the R, S, T three-phase interfaces of the controllable rectifier feedback unit are connected to the external power supply, and the U, V, W three-phase interfaces of the inverter unit are connected to the motor M. The controllable rectifier feedback unit and the inverter unit are connected in parallel through the DC bus PN, where P is the positive terminal and N is the negative terminal. The controllable rectifier feedback unit includes six insulated gate bipolar transistors (IGBT) G1 to G6. The IGBT is a composite device that combines the input characteristics of MOSFET (insulated gate field effect transistor) and the output characteristics of BJT (bipolar transistor). Its main features include high input impedance and high current density, and it is suitable for high power and high voltage applications. The embodiment of the utility model inverts DC power into AC power through IGBT, and controls the speed and torque of the motor through fast switching. The structure of the inverter unit and its effect do not need to be reflected in this scheme, so they are not repeated here.

[0035] Specifically, in the embodiment of the utility model, a single-phase power supply is used as a backup rescue energy source, which is put into practical use when the external power supply is disconnected. The single-phase power supply can be converted into AC220V alternating current or 380V direct current after being boosted by a battery.

[0036] In the first embodiment of the utility model, when the external power supply is disconnected, the single-phase power supply of the utility model is as follows Figure 1 As shown, two phase interfaces R and S are connected, and the T interface is configured as an additional phase interface.

[0037] Then use one end of the energy dissipation device to connect to the T interface and the other end to the DC bus. Figure 1As shown in the figure, when connected to the N terminal, the T interface, the energy-consuming device, the N terminal, the G6 IGBT, and the T interface form a loop and are connected in parallel to the DC bus. Since a single-phase power supply is connected at this time, the G1-G6 IGBTs of the controllable rectifier feedback unit cannot work, and the inverter unit works normally, converting the single-phase power supply into three-phase power to control the motor M to work as usual, realizing the operation of the elevator emergency rescue mode.

[0038] Similarly, when the other end of the energy-consuming device is connected to the P terminal of the DC bus, then Figure 1 It can be seen that the G5 IGBT will participate in the formation of the parallel circuit. The G5 IGBT and the G6 IGBT have similar functional structures. Therefore, the new parallel circuit has the same function as the above circuit.

[0039] The above is a function of controlling the motor M by the power supply during the elevator's recovery operation. However, there is also a situation where the motor generates electricity for the power supply during the elevator's operation.

[0040] Taking Figure 1 the connection method as an example, when the motor M controls the elevator to descend, the gravitational potential energy is converted into three-phase electrical energy, and then the three-phase voltage is converted into a DC voltage through the inverter unit and maintained at both ends of the DC bus PN. At this time, the G6 IGBT and the energy-consuming device are connected in parallel to the DC bus. Therefore, by controlling the on and off of the G6 IGBT, the operation of the energy-consuming device can be realized, and the electrical energy on the DC bus can be gradually converted into heat energy, thus ensuring that the electricity generated by the motor can be directly dissipated and does not need to be stored in the backup rescue power supply. Therefore, the backup rescue power supply does not need to use a complex and expensive three-phase inverter power supply and can directly use a single-phase power supply.

[0041] In addition, in the embodiment of the present invention, the control element can be a sectional contactor, a controllable sectional semiconductor, or a power relay. Among them, the sectional contactor is used to control the access and disconnection of the energy-consuming resistor, the controllable sectional semiconductor (such as IGBT or MOSFET) is used to accurately control the access of the energy-consuming resistor, and can quickly respond and achieve more refined energy management; the power relay is used to switch the connection of the energy-consuming resistor and has high switching ability and reliability. It can be selected according to the working scenario.

[0042] Furthermore, in the embodiment of the present invention, it can be seen from the above process that when the external power supply works, the controllable rectifier feedback unit and the inverter unit of the four-quadrant frequency converter work normally; when the external power supply does not work, or when a smaller range of current generated by the motor M needs to be consumed, the energy-consuming device can be connected to the four-quadrant frequency converter. Therefore, the control element can be controlled to be turned on and off by the single-phase power supply, or can be controlled to be turned on and off by the four-quadrant frequency converter.

[0043] In addition, in another embodiment of the present utility model, the energy consumption device can be used as a fast discharge circuit function of the DC bus.

[0044] Furthermore, in the second embodiment of the present utility model, when the external power supply is disconnected, a single-phase power supply can be connected to the R and T phase interfaces of the controllable rectifier feedback unit, and then the S interface is called an additional phase interface and is connected to the energy consumption device. At this time, if the other end of the energy consumption device is connected to the N terminal, the G4 IGBT participates in the energy consumption loop; if the other end of the energy consumption device is connected to the P terminal, the G3 IGBT participates in the energy consumption loop.

[0045] In the embodiment of the present utility model, the G1-G6 IGBTs of the controllable rectifier feedback unit are the same. According to the principle of the first embodiment above, it is still possible to use an economical single-phase power supply as a backup power supply for rescue without changing the structure of the original four-quadrant frequency converter.

[0046] Similarly, when a single-phase power supply is connected to the S and T phase interfaces of the controllable rectifier feedback unit, the R interface is connected to the energy consumption device, and the G1 and G2 IGBTs participate in the energy consumption.

Claims

1. A circuit for starting the energy consumption braking of a four - quadrant frequency converter using a single - phase power supply, characterized in that, The circuit includes: a four - quadrant frequency converter, an external power supply, a single - phase power supply, a power - consuming device, and a motor; the four - quadrant frequency converter includes a controllable rectifier feedback unit and an inverter unit, and the controllable rectifier feedback unit and the inverter unit are connected in parallel through a DC bus; the external power supply is connected to the R, S, and T three - phase interfaces of the controllable rectifier feedback unit; the single - phase power supply is connected to any two of the R, S, and T three - phase interfaces of the controllable rectifier feedback unit, and the unconnected phase interface is configured as an additional phase interface; the power - consuming device includes a control element and a power - consuming resistor, one end of the power - consuming device is connected to the additional phase interface, and the other end of the power - consuming device is connected to any terminal of the DC bus; the motor is connected to the inverter unit; when the external power supply is powered on, the single - phase power supply and the power - consuming device are both disconnected from the four - quadrant frequency converter; when the external power supply is disconnected, the single - phase power supply and the power - consuming device are both connected to the four - quadrant frequency converter.

2. The circuit for starting the energy consumption braking of a four-quadrant frequency converter using a single-phase power supply according to claim 1, wherein the controllable rectifier feedback unit includes 6 insulated gate bipolar transistors; when the single - phase power supply supplies power to the motor, the additional phase interface, the power - consuming device, and the target insulated gate bipolar transistor in the controllable rectifier feedback unit are connected in parallel to the DC bus, so that the single - phase power supply cannot drive the controllable rectifier feedback unit, but can drive the inverter unit to control the motor; when the motor supplies power to the single - phase power supply, the DC bus voltage rises, the on - off of the target insulated gate bipolar transistor is controlled, and the power - consuming device is used to consume the power of the DC bus, so that the power generated by the motor can be consumed through the energy - consuming device.

3. The circuit for starting the energy consumption braking of a four - quadrant frequency converter using a single - phase power supply according to claim 1, wherein, the control element is a sectional contactor, a controllable sectional semiconductor, or a power relay.

4. The circuit for starting the energy consumption braking of a four - quadrant frequency converter using a single - phase power supply as described in claim 3, wherein the on - off of the control element is controlled by the single - phase power supply.

5. The circuit for starting the energy consumption braking of a four-quadrant frequency converter using a single-phase power supply as described in claim 3, characterized in that, the on - off of the control element is controlled by the four - quadrant frequency converter.

6. The circuit for starting the energy consumption braking of a four-quadrant frequency converter using a single-phase power supply according to any one of claims 1 to 5, characterized in that, the external power supply is a three - phase power supply network.

7. The circuit for starting the energy consumption braking of a four-quadrant frequency converter using a single-phase power supply according to any one of claims 1 to 5, characterized in that, the single - phase power supply is inverted to output alternating current or direct current after being boosted by a battery.

8. The circuit for starting the energy consumption braking of a four - quadrant frequency converter using a single - phase power supply according to any one of claims 1 to 5, wherein, the motor is a three - phase motor.

9. The circuit for starting the energy consumption braking of a four-quadrant frequency converter using a single-phase power supply as described in claim 1, wherein the power - consuming device is used as a fast - discharge circuit for the DC bus.

10. A device, characterized in that, The device includes: the circuit for starting the four - quadrant frequency converter and performing energy - consuming braking using a single - phase power supply according to any one of claims 1 - 9 above.

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