CN218788721U

CN218788721U - Modular active filter

Info

Publication number: CN218788721U
Application number: CN202223213659.4U
Authority: CN
Inventors: 李宏刚; 李育春; 张海兵; 袁爱庆; 王红美; 高辉
Original assignee: XI'AN ACTIONPOWER ELECTRIC CO LTD; China Railway Design Corp
Current assignee: XI'AN ACTIONPOWER ELECTRIC CO LTD; China Railway Design Corp
Priority date: 2022-11-23
Filing date: 2022-11-23
Publication date: 2023-04-04
Anticipated expiration: 2032-11-23

Abstract

The utility model discloses a modular active filter, belonging to the technical field of filters, comprising a control circuit, a drive circuit, an auxiliary power circuit, an inverter circuit, a DCDC circuit and a filter circuit; the method is characterized in that: the filter circuit is arranged on the upper surface of the shell; the inverter circuit is positioned above the filter circuit, and the lower surface of the inverter circuit is not contacted with the upper surface of the filter circuit; the driving circuit, the auxiliary power supply circuit and the DCDC circuit are arranged on the upper surface of the inverter circuit; the filter circuit is connected with the inverter circuit through a contact pin; the filter circuit is provided with an interface for connecting the load current transformer and the power grid; the inverter circuit is respectively connected with the control circuit, the driving circuit, the auxiliary power supply circuit and the DCDC circuit through the contact pin. The utility model discloses on distributing active filter's function to different circuit boards, through the interface interconnection, constitute modular active filter complete machine, the dismouting is more convenient.

Description

Modular active filter

Technical Field

The utility model belongs to the technical field of the wave filter, especially, relate to a modular active filter.

Background

Reactive power (inductive or capacitive), current harmonic and negative sequence current have serious influence on the stable and efficient operation of a power system. There is a desire among power consumers to reduce grid system reactive and harmonic. It is widely recognized that the optimal management scheme for reactive power and current harmonics is in-situ treatment.

Most of the existing active filters (APFs) are manufactured as a plug-in box and installed in an active filter cabinet, and the active filter cabinet is connected to an alternating current bus. The scheme focuses on treating all harmonic current and reactive power of a section of alternating current bus. In this mode, the harmonic current is not injected into the superior distribution network of the bus bar of the section, but in the bus bar of the section, the harmonic current still flows between the devices, which affects the operation of the devices connected to the bus bar of the section.

SUMMERY OF THE UTILITY MODEL

To above technical defect, the utility model provides a modular active filter for compensate the modular active filter that electric power load is idle, filtering electric power system harmonic and eliminate negative sequence electric current in situ, distribute the circuit board of difference through the function with active filter on, through the interface interconnection, constitute modular active filter complete machine, the dismouting is more convenient.

In order to achieve the technical purpose, the utility model discloses a following technical scheme realizes:

a modular active filter comprises a control circuit, a drive circuit, an auxiliary power circuit, an inverter circuit, a DCDC circuit and a filter circuit; the filter circuit is arranged on the upper surface of the shell; the inverter circuit is positioned above the filter circuit, and the lower surface of the inverter circuit is not in contact with the upper surface of the filter circuit; the driving circuit, the auxiliary power supply circuit and the DCDC circuit are arranged on the upper surface of the inverter circuit; wherein: the filter circuit is connected with the inverter circuit through a contact pin; the filter circuit is provided with an interface for connecting the load current transformer and the power grid; the inverter circuit is respectively connected with the control circuit, the driving circuit, the auxiliary power circuit and the DCDC circuit through the contact pins.

Preferably: the fan control circuit is connected with the filter circuit through a contact pin; the filter circuit is connected with the fan through a pin.

Preferably: the fan includes a first fan and a second fan.

The utility model has the advantages and the technical effect be:

1. the functions of the active filter are distributed to different circuit boards and are interconnected through the interfaces to form a modular active filter complete machine, and the assembly and disassembly are convenient.

2. Through the stacking installation of the functional circuit boards, the direct-insertion connection of the circuit interfaces is beneficial to improving the power density of the active filter.

3. The active filter module can be embedded into a user cabinet so as to realize the local treatment of the power quality.

Drawings

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

fig. 2 is a structural diagram of the present invention.

In the figure: 1. a control circuit; 2. a drive circuit; 3. an auxiliary power supply circuit; 4. an inverter circuit; 5. a DCDC circuit; 6. a filter circuit; 7. a fan control circuit; 8. a first fan; 9. a second fan.

Detailed Description

In order to make the above objects, design ideas, and advantages of the present invention more apparent, the present invention will be described in further detail with reference to the following embodiments. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the invention.

Referring to fig. 1 and 2, a modular active filter includes a control circuit 1, a driving circuit 2, an auxiliary power circuit 3, an inverter circuit 4, a DCDC circuit 5, a filter circuit 6, a fan control circuit 7, a first fan 8 and a second fan 9; wherein: the circuits are mounted in a stacked mode, the specific connection relation is shown in figure 1, and all the components are directly connected in a pin and jack mode.

The function of the filter circuit is: the method comprises the steps of providing an interface for connecting a three-phase four-wire system power grid, providing the fusing protection of commercial power input, LCL filtering at an input side, soft start control, power grid voltage sampling and load current sampling. And providing connection interfaces with the fan control circuit, the first fan and the second fan. An interface to the inverter circuit is provided.

The inverter circuit functions as: and providing a main circuit interface with a filter circuit, sampling current at an alternating current side, performing three-phase full-bridge power conversion, providing a direct current bus support, performing overheating, overcurrent protection and emergency stop control logic processing, and sampling voltage of the direct current bus. Interfaces are provided with an auxiliary power supply circuit, a control circuit, a driving circuit, a DCDC circuit and a filter circuit. An interface to external communication connections is provided. The inverter circuit uses a SiC MOS tube as a main power device.

The auxiliary power supply circuit functions as: by using the DC bus voltage, 4 groups of independent working power supplies are generated by an on-board isolation switch power supply circuit and are provided for each circuit of the modular active filter. A connection interface with the inverter circuit is provided.

The DCDC circuit functions as: 4 groups of independent 24V working power supplies provided by the auxiliary power supply circuit are utilized to provide two groups of stable 24V working power supplies and two groups of stable 5.1V working power supplies through a voltage stabilizing circuit. And providing a connection interface with the inverter circuit.

The function of the control circuit is: the load power factor, the harmonic current and the negative sequence current are calculated by measuring the load current and the power grid voltage, a controller is utilized to operate a control algorithm, three-phase PWM waves are emitted, the inverter circuit is controlled to work through a driving circuit, and the controlled current is output to improve the load power factor and eliminate the load current harmonic. The control circuit provides a connection interface with the inverter circuit.

The function of the drive circuit is: the power amplification and isolation are carried out on the three-phase PWM wave sent by the control circuit, the transistor switch on the inverter circuit is driven to act, and the protection of the transistor on the inverter circuit is provided. The driving circuit provides a connection interface with the inverter circuit.

The function of the fan control circuit is: the rotating speed of the radiating fan is adjusted according to the load current or (and) the temperature of the inverter circuit radiator so as to realize the control of noise. The fan control circuit provides a connection interface with the filter circuit.

The first fan and the second fan have the functions of: and carrying out air-cooled forced heat dissipation on the inverter circuit radiator. The first fan and the second fan are connected to the filter circuit.

In the preferred embodiment:

an XS13 plug of the control circuit 1 is connected with an XS13 socket of the inverter circuit 4 through a 200-core contact pin, and the control circuit 1 obtains a working power supply, a load current signal, a power grid voltage signal, an output current signal, a state signal and a communication signal from the inverter circuit 4 through the 200-core plug; the control circuit 1 sends a state signal, a PWM driving signal and a communication signal to the inverter circuit through the 200-core contact pin. The DSP is internally preset with a compensation target parameter, a filtering target parameter and a negative sequence adjustment target parameter, and sets a priority order.

The XS1 plug of the driving circuit 2 is connected with the XS1 socket on the inverter circuit 4 through a 51-core pin. The drive circuit 2 obtains working power from a direct current bus of the inverter circuit 4 through the 51-core plug, and converts the working power into 6-way 18V drive power through a switching power supply on a board. The drive circuit 2 obtains the PWM drive signal from the inverter circuit 4 through the 51-core plug, and outputs 6 independent drive signals with the amplitude of minus 5V to plus or minus 18V after the control, amplification and isolation of the dead zone on the board, and the drive signals are transmitted to an XS1 socket of the inverter circuit 4 through the 51-core pin.

And an XS1 plug of the auxiliary power circuit 3 is connected with an XS2 socket of the inverter circuit 4 through a 6-core contact pin, so that the DC bus voltage provided by the inverter circuit is obtained. In the auxiliary power circuit 3, after the dc bus voltage is isolated and transformed by the switching power supply, 4 paths of dc power including 1 path +/-5v1a, 1 path-5v200ma, 1 path 24v37w and 1 path 24V3W are output to the XS2 socket of the inverter circuit through the 6-core pin.

The XS1 plug of the DCDC circuit 5 is connected with the XS9 socket of the inverter circuit 4 through 16-core pins. The DCDC circuit 5 obtains a 24V3W input power supply, obtains a first path of 24V stable power supply after the isolation and transformation of a switching power supply, and outputs the first path of 24V stable power supply to the inverter circuit 4 through the 16-core contact pin; the DCDC power supply 5 obtains +/-5V 1A and-5V 200mA power supplies, obtains +/-5V and-5V power supplies after the conversion and the filtering of the switch power supply, and outputs the power supplies to the inverter circuit 4 through the 16-core pin; the DCDC power supply 5 obtains a 24V37W power supply, a second path of 24V stable power supply is obtained after the conversion and the filtering of the switching power supply, and the second path of 24V stable power supply is output to the inverter circuit 4 through the 16-core contact pin.

An XS6 plug of the filter circuit 6 is connected with an XS6 socket of the inverter circuit 4 through a 34-core pin, and an XS7 plug of the filter circuit 6 is connected with an XS7 socket of the inverter circuit 4 through a 4-core pin. The filter circuit 6 has an XS1 terminal with 4 positions for connecting to the grid. The A/B/C/N phase voltage from the power grid enters a filter circuit 6, then sequentially passes through a fuse and an LCL filter circuit, passes through a soft start circuit formed by connecting a resistor and a switch in parallel, and then is sent to an XS7 socket of an inverter circuit 4 through the 4-core contact pin. On the filter circuit 6, the voltage of the power grid is sampled in a resistance voltage division mode and is transmitted to the inverter circuit 4 through the 34-core contact pin; at the filter circuit 6, the load current is sampled by a current sensor to obtain a load current signal, which is sent to the inverter circuit 4 through the 34-core pin. The filter circuit 6 also obtains working power supply, a state signal and an output current signal through the 34-core pin.

The XS1 plug of the fan control circuit 7 is connected with the XS8 socket of the filter circuit 6 through 8-core pins. The fan control circuit 7 obtains the 24V37W power supply from the filter circuit 6, the temperature signal of the modular active filter and the output current signal. The fan control circuit 7 obtains two controlled voltages according to the temperature signal and the output current signal, and the two controlled voltages are sent to the filter circuit 6 through the 8-core contact pin.

The first fan 8 and the second fan 9 are speed-regulating fans with a rated working voltage of 24V, and are respectively connected to an XS4 socket and an XS5 socket of the filter circuit 6, and when the voltages of the XS4 socket and the XS5 socket change, the rotating speed of the fans changes along with the voltage.

The inverter circuit 4 samples the output current of the modular filter through the current hall to obtain an output current signal; the switching frequency of the inverter circuit 4 is 90kHz; the 14 150uF450V electrolytic capacitors are used for forming a direct current bus in a 2-series 7-parallel mode, output current control and direct current bus voltage control are completed under the control of a driving signal, and the functions of power factor compensation, harmonic current filtering and negative sequence current elimination of the modular filter are realized.

Description of the start-up procedure of the modular active filter: after the input power is switched on, the current from the power grid flows through a fuse, an LCL circuit and a soft start resistor on the filter circuit 6 in sequence and is transmitted to an XS6 port of the inverter circuit 4 through an XS6 port of the filter circuit 6. And the direct current bus is charged through body diodes of six MOS tubes on the inverter circuit 4. The DC bus voltage is transmitted to an XS1 port of the auxiliary power supply circuit 3 through an XS2 port of the inverter circuit 4, and the auxiliary power supply circuit 3 starts to work after being electrified. The output of the auxiliary power supply circuit 3 is connected to an XS2 port of the inverter circuit 4 through an XS1 port thereof, and is connected to an XS1 port of the DCDC circuit 5 through an XS9 port of the inverter circuit 4. The DCDC circuit 5 starts working after being electrified, and a working power supply is established and is sent to an XS9 port of the inverter circuit 4 through an XS1 port of the DCDC circuit 5. So far, the modular active filter working power supply is established. And a timing circuit is arranged on the filter circuit 6, and the soft start switch on the filter circuit 6 is controlled to be closed after being electrified for a certain time to finish soft start. To this end, the modular active filter enters an operational state.

To sum up, the embodiment of the present invention provides a modular active filter. The active filter has the characteristics of small volume and high power density, can be installed in electric equipment, and realizes local management on electric energy quality parameters.

The above description is only exemplary of the present invention and should not be construed as limiting the present invention, and any modifications, equivalents and improvements made within the spirit and principles of the present invention are intended to be included within the scope of the present invention.

Claims

1. A modular active filter comprises a control circuit (1), a drive circuit (2), an auxiliary power circuit (3), an inverter circuit (4), a DCDC circuit (5) and a filter circuit (6); the method is characterized in that: the filter circuit (6) is arranged on the upper surface of the shell; the inverter circuit (4) is positioned above the filter circuit (6), and the lower surface of the inverter circuit (4) is not in contact with the upper surface of the filter circuit (6); the driving circuit (2), the auxiliary power circuit (3) and the DCDC circuit (5) are arranged on the upper surface of the inverter circuit (4); wherein: the filter circuit (6) is connected with the inverter circuit (4) through a contact pin; the filter circuit (6) is provided with an interface for connecting the load current transformer and a power grid; the inverter circuit (4) is respectively connected with the control circuit (1), the driving circuit (2), the auxiliary power circuit (3) and the DCDC circuit (5) through contact pins.

2. The modular active filter according to claim 1, characterized in that: the fan control circuit (7) is connected with the filter circuit (6) through a contact pin; the filter circuit (6) is connected with the fan through a pin.

3. The modular active filter according to claim 2, characterized in that: the fan comprises a first fan (8) and a second fan (9).