CN217769478U

CN217769478U - High-power network current limiting circuit

Info

Publication number: CN217769478U
Application number: CN202221284475.4U
Authority: CN
Inventors: 谢鹏; 蒋健; 林德品; 樊素梦
Original assignee: Guangxi Daoji Medical Equipment Co ltd
Current assignee: Guangxi Daoji Medical Equipment Co ltd
Priority date: 2022-05-26
Filing date: 2022-05-26
Publication date: 2022-11-08
Anticipated expiration: 2032-05-26

Abstract

The utility model provides a high-power grid current limiting circuit, which comprises a current limiting unit, a rectifying and filtering unit, a capacitor energy storage unit, a main inversion unit, a main control unit and a high-voltage oil tank; the input end of the current limiting unit is connected with a 220V AC power grid, and the output end of the current limiting unit is connected with the rectifying and filtering unit; the current limiting unit comprises a resistor R1 and a resistor R2 which are connected in parallel, and the current limiting unit sends out an instruction for control through the main control unit. The utility model discloses a circuit structure is simple, and reasonable in design through set up the current limiting unit between electric wire netting power and rectification filtering unit, can effectually avoid drawing down the defect of electric wire netting mains voltage that X ray high voltage generator during operation arouses, guarantees the normal work of other consumer.

Description

High-power network current limiting circuit

Technical Field

The utility model belongs to the technical field of electric power, in particular to high-power net electric current limiting circuit.

Background

For the application occasions where the power grid is unstable, the high-power X-ray high-voltage generator adopts an energy storage power supply mode, and a stable ray source can be obtained without depending on the power grid too much. The method specifically comprises the following steps: firstly, a small-current power grid is adopted to charge a capacitor energy storage unit of an X-ray high-voltage generator until the capacitor energy storage unit is full, when the X-ray high-voltage generator works, energy provided by the power grid and the capacitor energy storage unit is consumed, and the X-ray machine can output stable current (mA) and high voltage (kV), so that the clinical requirement of X-ray photography is met.

Most of the current single-phase high-power (more than 10 kW) high-voltage generators adopt a capacitive energy storage type power supply mode, and a capacitive energy storage unit is directly connected with a power grid. When the X-ray high-voltage generator works, the electric quantity of a power grid and the electric quantity of the capacitor energy storage unit are consumed, the exposure time is too long, after the electric quantity of the capacitor energy storage unit is discharged, the power grid power supply voltage is pulled to be very low, the voltage is pulled from 220V to about 150V, the normal work of other electric equipment is influenced, the problems of computer restart, illuminating lamp flicker and the like can occur, and even tripping, power failure and the like of a main switch can be caused in severe cases. If the problem is solved by increasing the capacity of the capacitive energy storage unit, the size and the weight of the X-ray high-voltage generator are increased, and the final use cost is greatly increased.

SUMMERY OF THE UTILITY MODEL

The electric wire netting mains voltage who exists is drawn low in using to present high-power high voltage generator, influences the defect that other power consumptions do not establish normal work, the utility model provides a high-power net electricity current-limiting circuit effectively reduces the influence of high voltage generator during operation to electric wire netting mains voltage.

The utility model discloses a realize through following technical scheme:

a high-power grid current limiting circuit comprises a current limiting unit, a rectifying and filtering unit, a capacitive energy storage unit, a main inverter unit, a main control unit and a high-voltage oil tank;

the current limiting unit, the rectifying and filtering unit, the capacitive energy storage unit and the high-voltage oil tank are sequentially connected in series and are respectively connected with the main control unit in parallel;

the input end of the current limiting unit is connected with a 220V AC power grid power supply, and the output end of the current limiting unit is connected with the rectifying and filtering unit; the current limiting unit comprises two resistors R1 and R2 which are connected in parallel, the resistor R1 is connected with the switch K1 in series and is connected to the rectifying and filtering unit 2, and the resistor R2 is connected with the switch K2; the switch K1 and the switch K2 are respectively controlled by an instruction sent by the main control unit 5.

Preferably, the resistance of the resistor R1 is 100 Ω, and the power is 100W.

Preferably, the resistance value of the resistor R2 is 5 Ω, and the power is 500W.

The utility model discloses a theory of operation as follows:

before the X-ray high-voltage generator works, the main control unit controls the switch K1 of the current limiting unit to be closed, so that 220V AC of a power grid power supply carries out low-current charging on the rectifying and filtering unit and the capacitor energy storage unit through a resistor R1 of 100 omega/100W in the current limiting unit, and the low-current charging cannot influence the power grid power supply. After the capacitor energy storage unit is fully charged, the switch board K2 is closed through a control command of the main control unit, the two ends of the 100 omega/100W resistor R1 are connected with the 5 omega/400W resistor R2 in parallel, and then the X-ray high-voltage generator can work normally.

When the X-ray high-voltage generator works, the current limiting unit of about 4.8 omega is connected in series in the middle of the power grid power supply and the rectifying and filtering unit, the main control unit sends a control command to enable the main inversion unit and the high-voltage oil tank to work, when the X-ray high-voltage generator works and outputs high power, a large amount of electric quantity of the capacitive energy storage unit is consumed, and meanwhile, a part of energy can be consumed from the power grid power supply.

The utility model has the advantages as follows:

the utility model discloses a circuit structure is simple, and reasonable in design through set up the current-limiting unit between grid power and rectification filtering unit, can effectually avoid drawing down grid power voltage's that X ray high voltage generator during operation arouses defect, guarantees other consumer's normal work.

Drawings

Fig. 1 is a schematic diagram of the circuit of the present invention.

Fig. 2 is a connection frame diagram of the circuit of the present invention.

Reference numerals: the device comprises a current limiting unit 1, a rectifying and filtering unit 2, a capacitive energy storage unit 3, a main inverter unit 4, a main control unit 5 and a high-voltage oil tank 6.

Detailed Description

The present invention will be further explained with reference to the accompanying drawings.

Example 1

As shown in fig. 1 and 2, the current-limiting circuit for high-power grid power supply comprises a current-limiting unit 1, a rectifying and filtering unit 2, a capacitive energy storage unit 3, a main inverter unit 4, a main control unit 5 and a high-voltage oil tank 6;

the current limiting unit 1, the rectifying and filtering unit 2, the capacitor energy storage unit 3 and the high-voltage oil tank 6 are sequentially connected in series and are respectively connected with the main control unit 5 in parallel;

the input end of the current limiting unit 1 is connected with a 220V AC power grid, and the output end of the current limiting unit is connected with the rectifying and filtering unit 2; the current limiting unit 1 comprises two resistors R1 and R2 which are connected in parallel, the resistor R1 is connected with the switch K1 in series and is connected to the rectifying and filtering unit 2, and the resistor R2 is connected with the switch K2; the switch K1 and the switch K2 are respectively controlled by an instruction sent by the main control unit 5.

The resistance of the resistor R1 is 100 omega, and the power is 100W.

The resistance value of the resistor R2 is 5 omega, and the power is 500W.

The working principle of the implementation is as follows:

1. charging of the high voltage generator: after a 220V network power supply is connected by a high-voltage generator, a starting-up instruction is sent out through a main control unit 5 to control a switch K1 alternating current contactor to be attracted, the 220V network power supply charges a capacitor energy storage unit 3 through a resistor R1 (100 omega/100W) through a rectification filtering unit 2, when the capacitor energy storage unit 3 is charged to 80%, the main control unit 5 sends out an instruction to control a switch K2 alternating current contactor to be attracted, and the resistor R2 (5 omega/500W) is connected with a resistor R1 (100 omega/100W) in parallel and charges the capacitor energy storage at the same time until the capacitor energy storage unit is fully charged.

2. Operation of the high voltage generator: give the exposure instruction through main control unit 5, control

main inverter

4 and 6 work of high-pressure oil tank, high-pressure generator exports 20 kW's high-power in the twinkling of an eye, and the exposure in-process consumes the electric quantity in the electric capacity energy storage unit rapidly, and when electric capacity of electric capacity energy storage unit was not enough, high-pressure generator can pass through the electric wire netting power consumption electric quantity. If the rectifying and filtering unit 2 is directly connected with the power supply of the power grid, a large current can be generated instantly, and the voltage of the power supply of the power grid is directly reduced to be below 150V. However, with the current limiting unit 1, the inverter current of the high-voltage generator is larger, and the current output by the point network power supply cannot be increased infinitely because the rectifying and filtering unit 2 connected with the network power supply has a current limiting resistor of about 4.8 omega/600W.

The above embodiments are only exemplary embodiments of the present invention, and are not intended to limit the present invention, and the protection scope of the present invention is defined by the claims. Various modifications and equivalents of the invention may be made by those skilled in the art within the spirit and scope of the invention, and such modifications and equivalents should also be considered as falling within the scope of the invention.

Claims

1. A high-power net current limiting circuit is characterized in that: the device comprises a current limiting unit (1), a rectifying and filtering unit (2), a capacitance energy storage unit (3), a main inversion unit (4), a main control unit (5) and a high-voltage oil tank (6);

the current limiting unit (1), the rectifying and filtering unit (2), the capacitive energy storage unit (3) and the high-voltage oil tank (6) are sequentially connected in series and are respectively connected with the main control unit (5) in parallel;

the input end of the current limiting unit (1) is connected with a 220V AC power grid power supply, and the output end of the current limiting unit is connected with the rectifying and filtering unit (2); the current limiting unit (1) comprises two resistors R1 and R2 which are connected in parallel, the resistor R1 and the switch K1 are connected in series and connected to the rectifying and filtering unit (2), and the resistor R2 is connected with the switch K2; the switch K1 and the switch K2 are respectively controlled by an instruction sent by a main control unit (5).

2. The high power grid current limiting circuit of claim 1, wherein the group of characteristics comprises: the resistance of the resistor R1 is 100 omega, and the power is 100W.

3. The high power grid current limiting circuit of claim 1, wherein: the resistance value of the resistor R2 is 5 omega, and the power is 500W.