CN211830243U

CN211830243U - Charging and inverting integrated circuit

Info

Publication number: CN211830243U
Application number: CN201922148472.2U
Authority: CN
Inventors: 谢力华; 冯光辉
Original assignee: Shenzhen Ecowatt Power Co ltd
Current assignee: Shenzhen Ecowatt Power Co ltd
Priority date: 2019-12-04
Filing date: 2019-12-04
Publication date: 2020-10-30
Anticipated expiration: 2029-12-04

Abstract

The utility model discloses a charging inversion integrated circuit, which comprises a first connecting terminal connected with a storage battery, a second connecting terminal connected with an alternating current power supply, a third connecting terminal connected with a load, a direct current soft start module, a PWM converter, a transformer, a first switch and a second switch; the secondary side of the transformer is connected with the second wiring terminal through the first switch and is connected with the third wiring terminal through the second switch; the input end of the PWM converter is connected with the anode of the first wiring terminal through the direct-current soft start module, and the output end of the PWM converter is connected with the primary side of the transformer; when the first switch is switched off and the second switch is switched off, the PWM converter inverts the direct current output by the storage battery into alternating current and outputs the alternating current to the primary side of the transformer; and when the first switch is closed and the second switch is opened, the PWM converter rectifies the alternating current of the primary side of the transformer and outputs the rectified alternating current to the first connecting terminal. The circuit has the advantages of small volume, light weight, low manufacturing cost and strong reliability.

Description

Charging and inverting integrated circuit

Technical Field

The utility model relates to a power electronic equipment field especially relates to an integrative circuit of contravariant charges.

Background

The traditional alternating current inversion off-grid power supply system is provided with an independent charger and an inverter, the inverter is generally large in power configuration, the charger is low in power configuration in order to reduce the cost, the size and the weight of the system, the charging time of a storage battery is long due to the configuration, the flexibility of the system is low, quick response is not facilitated, and the defect is particularly obvious in an on-vehicle inversion-charging system. If a charger with higher power is configured, the volume and the weight of the off-grid power supply system are larger, and the cost is higher. This discrepancy is difficult to reconcile.

In addition, in order to realize the reverse connection prevention protection function of the storage battery in the traditional off-grid inversion and charging system, a reverse stopping diode is usually connected in series on a direct current loop, the reverse stopping diode can bring inherent conduction loss, the reverse connection prevention protection system is particularly obvious in a direct current low-voltage system, the backup time of the storage battery can be reduced due to low efficiency, and meanwhile, the additional heating can bring reliability hidden trouble to the system.

Disclosure of Invention

Volume and weight to traditional off-grid contravariant and charging system are big, and the cost of manufacture is high and the low scheduling problem of system reliability, the embodiment of the utility model provides a charging contravariant integrated circuit.

The embodiment of the utility model provides a solve the method that above-mentioned problem adopted and be: the utility model provides a integrative circuit of contravariant charges, the circuit is including the first binding post of connecting storage battery, the second binding post of connecting alternating current power supply to and the third binding post of connecting load, its characterized in that, the circuit still includes: the device comprises a direct current soft start module, a PWM converter, a transformer, a first switch and a second switch; the secondary side of the transformer is connected with the second connecting terminal through the first switch and is connected with the third connecting terminal through the second switch;

the input end of the PWM converter is connected with the first wiring terminal through the direct current soft start module, and the output end of the PWM converter is connected with the primary side of the transformer; when the first switch is switched off and the second switch is switched off, the PWM converter inverts the direct current output by the storage battery into alternating current and outputs the alternating current to the primary side of the transformer; and when the first switch is closed and the second switch is opened, the PWM converter rectifies the alternating current of the primary side of the transformer and outputs the rectified alternating current to the first connecting terminal.

Preferably, the direct current soft start module includes contactor, soft resistance and diode of starting, just soft resistance of starting with diode series connection back, parallel connection is in the both ends of contactor, wherein the negative pole of diode with the contactor is connected, the positive pole of diode with soft resistance of starting is connected.

Preferably, the transformer is a single-phase transformer, and the circuit further comprises a fuse and an automatic switch which are sequentially connected in series to a live wire on the secondary side of the transformer.

Preferably, the PWM converter includes two-phase bridge arms, and each phase bridge arm includes an upper bridge arm switching tube and a lower bridge arm switching tube.

Preferably, the transformer is a three-phase transformer, and the circuit further comprises a plurality of fuses and automatic switches which are sequentially connected in series on each phase line of the secondary side of the three-phase transformer.

Preferably, the PWM converter includes three-phase bridge arms, and each phase bridge arm includes an upper bridge arm switching tube and a lower bridge arm switching tube.

Preferably, the circuit further comprises a third switch connected with the first connection terminal, wherein one end of the third switch is connected to the front end of the dc soft start module, and the other end of the third switch is connected to the negative electrode of the first connection terminal.

Preferably, the circuit further includes a first inductor and a first capacitor, the first inductor is connected between the positive electrode of the first connection terminal and the dc soft start module, one end of the first capacitor is connected to the output end of the dc soft start module, and the other end of the first capacitor is connected to the negative electrode of the first connection terminal.

Preferably, the upper bridge arm switch tube and the lower bridge arm switch tube are insulated gate bipolar transistors or metal oxide field effect transistors.

The charging and inverting integrated circuit adopts a single-stage PWM converter, can realize bidirectional power conversion, can work in a DC-AC inverting mode and can also work in an AC-DC rectifying and charging mode, wherein the inverting mode and the charging mode share one set of PWM power conversion circuit, and compared with an AC inverting off-grid power supply system formed by a traditional independent inverter and an independent charger, the size and the cost of power supply equipment are greatly reduced, and the difficulty of use and operation is also reduced. In addition, the charging and inverting integrated circuit is provided with a direct-current soft start module, the protection of the reverse connection prevention function of the storage battery is realized, the inverter replaces the traditional inverter to install a reverse-stopping diode in a direct-current input main loop to realize the loss of the efficiency of a converter caused by the reverse connection prevention function of the battery, the conversion efficiency of an inverting charging system is improved, the heating of the system is reduced, and the reliability is improved.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required to be used in the description of the embodiments of the present invention will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without inventive labor.

Fig. 1 is a circuit diagram of a charging and inverting integrated circuit according to an embodiment of the present invention;

fig. 2 is a circuit diagram of a charging and inverting integrated circuit according to another embodiment of the present invention;

fig. 3 is a circuit diagram of a charging and inverting integrated circuit according to another embodiment of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, not all, of the embodiments of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative efforts belong to the protection scope of the present invention.

The existing alternating current inversion off-grid power supply system taking a storage battery as an energy storage element, such as an electric vehicle-mounted charging and inversion system, generally comprises an independent charger and an independent inverter, under most application scenes, the charger and the inverter are mutually exclusive to work, namely, when the inverter works, the charger does not work, and when the charger works, the inverter does not work, under the application scenes, the system is huge in size, heavy in weight and high in cost due to the configuration of the independent charger and the independent inverter. For solving current alternating current contravariant that uses the battery as energy storage component from net power supply system big, the quality of system that leads to is heavy, with high costs, the operation inconvenient, the complicated reliability low grade shortcoming of structure at the machine of charging and dc-to-ac converter independent configuration, the utility model designs an one set of two-way converting circuit based on single-stage PWM converter, realized that a circuit can work in the inverter mode, also can work in the machine mode of charging, greatly reduced the volume, the weight and the cost of system.

Fig. 1 is a charging and inverting integrated circuit provided by an embodiment of the present invention, as shown in fig. 1, the circuit includes first connection terminals DC + and DC-connected to a storage battery, second connection terminals L1 and N1 connected to an ac power supply, and third connection terminals L2 and N2 connected to a load, a DC soft start module 10, a PWM converter 20, a transformer T1, a first switch K1, and a second switch K2; the secondary side of the transformer T1 is connected to the second connection terminal through the automatic switch K4, the inductor L2 and the first switch K1, and the secondary side of the transformer T1 is also connected to the third connection terminal through the automatic switch K4 and the second switch K2. The positive input end of the PWM converter 20 is connected to the positive electrode of the first connection terminal through the dc soft start module 10, the negative input end is connected to the negative electrode of the first connection terminal, and the output end of the PWM converter 20 is connected to the primary side of the transformer T1.

The charging and inverting integrated circuit can work in an inverting mode by controlling the first switch K1 to be opened and the second switch K2 to be closed, at this time, the direct current output by the storage battery pack is inverted into alternating current after passing through the direct current soft start module 10 and the PWM converter 20, and the alternating current is output to a load after being isolated by the transformer T1 to supply power to the load. The charging and inverting integrated circuit can also work in a charging mode by controlling the first switch K1 to be closed and the second switch K2 to be opened, at the moment, alternating current input by an alternating current power supply (such as a power grid) is isolated by the transformer T1, and the PWM converter 20 rectifies the alternating current to convert the alternating current into direct current and charges a storage battery pack connected to the first connecting terminal.

The charging and inverting integrated circuit realizes bidirectional power conversion through the single-stage PWM converter, can work in a direct current-alternating current inverting mode and can also work in an alternating current-direct current rectifying and charging mode, wherein the inverting mode and the charging mode share one set of PWM power conversion circuit, and compared with an alternating current inverting off-grid power supply system formed by a traditional independent inverter and an independent charger, the charging and inverting integrated circuit greatly reduces the size and the cost of power supply equipment and also reduces the difficulty of use and operation. In addition, because the machine that charges of system and dc-to-ac converter realize through same set of circuit, circuit structure is simple, and various electron and electric elements quantity only have about the half of the contravariant-charging system of leaving the net of traditional technical structure, the utility model discloses a circuit is more succinct, and the reliability is higher to realized the configuration of circuit equal power capacity under charge mode and contravariant mode, consequently improved the charge speed and the use flexibility of battery in the system greatly. In addition, in the embodiment, the direct-current soft start module is used for replacing a traditional non-return diode to perform reverse connection protection on the storage battery pack, so that heat generated when the circuit is reversely connected is reduced, and the reliability of the circuit is improved.

As shown in fig. 2, the utility model discloses a this soft start module of direct current 10 includes contactor KM1, soft resistance R and diode D1 of starting, and soft resistance R and diode D1 of starting are after series connection in proper order, connect at contactor KM 1's both ends, and wherein diode D1's negative pole is connected with the contactor, and diode D1's positive pole is connected with soft resistance R of starting. The soft start resistor R is used for input soft start current limiting, the diode D1 is used for direct current reverse connection prevention protection, and when the input positive electrode and the input negative electrode of the circuit are reverse connected, the direct current soft start loop is cut off due to reverse bias of the diode D1. The contactor KM1 is used for bypassing a direct current soft start loop, a control system gives a closing and opening instruction, when the contactor KM1 is opened, the input direct current is precharged to a steady-state voltage for a direct current bus capacitor C1 through a soft start resistor R and a diode D1, at the moment, the contactor KM1 is closed, and soft start is finished.

In the embodiment of the present invention, as shown in fig. 2, the transformer T1 may be a single-phase transformer, and in order to provide the enabling control (i.e. control whether the PWM converter works in the inversion mode or in the charging mode) when the PWM converter 20 performs the power conversion, the above circuit further includes a fuse F1 connected in series with the automatic switch SCR on the live wire of the secondary side of the transformer T1. The automatic switch SCR may specifically be a thyristor or a contactor, and when the circuit is operating in the inverter mode (i.e. the first switch K1 is closed), the automatic switch SCR may be disconnected from the transformer T1 to prevent the output terminal of the PWM converter 20 from being connected directly to the ac input connected to the second connection terminal. When the circuit works in a charging mode, before the direct current soft start is finished, the automatic switch SCR is switched off, and the alternating current input power supply is ensured not to be connected into the PWM converter 20, so that the alternating current input impacts a direct current bus through a diode which is connected with a power tube in an anti-parallel mode to cause overcurrent damage of a device. Fuse F1 provides overcurrent protection.

In the embodiment of the present invention, as shown in fig. 3, the transformer T1 may be a three-phase transformer. In order to provide enable control (i.e. to control whether the PWM converter operates in the inverter mode or in the charging mode) when the PWM converter 20 performs power conversion, the circuit further includes a plurality of fuses F1, F2, F3 and automatic switches SCR1, SCR2, SCR3 connected in series in sequence on each phase line of the secondary side of the three-phase transformer. The fuse is used for performing overcurrent protection on a circuit.

In addition, current sensors HAT1 and HAT2 may be respectively disposed at the positive electrode of the first connection terminal and the primary side of the transformer, and are respectively used for detecting the output current of the dc and PWM converters 20; a current sensor CT1 may be provided on the secondary side of the transformer for detecting the ac power to control and protect the PWM converter 20 by detecting the magnitude of the current signal.

As shown in fig. 2, in an embodiment of the present invention, the PWM converter includes two-phase bridge arms (Q1 and Q2), and each phase bridge arm includes an upper bridge arm switching tube and a lower bridge arm switching tube.

As shown in fig. 3, in another embodiment of the present invention, the PWM converter includes three-phase legs (Q1, Q2, and Q3), and each phase leg includes an upper leg switching tube and a lower leg switching tube.

In another embodiment of the present invention, a third switch K3 can be further disposed at the first connection terminal as a power switch of the circuit to control the charging and discharging of the battery. One end of the third switch K3 is connected to the front end of the DC soft start module 10, and the other end is connected to the negative electrodes of the first connection terminals DC + and DC-.

In the embodiment of the present invention, the circuit further includes a filter circuit composed of a first inductor L1 and a first capacitor C1, for filtering the direct current rectified by the PWM converter 20. The first inductor L1 is connected between the positive electrode of the first connection terminal and the dc soft start module 10, one end of the first capacitor C1 is connected to the output end of the dc soft start module, and the other end of the first capacitor C1 is connected to the negative electrode of the first connection terminal. Specifically, in the charging mode, the first capacitor C1 and the transformer T1 form a standard LCL filter for filtering high-frequency harmonic currents of the PWM converter 20 operating in the power factor correction rectification state, which can suppress the high-frequency harmonic currents from polluting the ac input power.

In the embodiment of the present invention, the rear end portion of the transformer further includes a filter circuit formed by a capacitor C2 and an inductor group L2, wherein, if the transformer is a single-phase transformer, the capacitor is connected between the zero line and the live line connected to the secondary side of the single-phase transformer, and the inductor is connected between the first switch K1 and the automatic switch; if the transformer is a three-phase transformer, a capacitor is connected between each phase line connected with the secondary side of the three-phase transformer and the zero line, and the inductance group L2 is connected to the front end of the third switch K3.

Specifically, in the charging mode and the inversion mode, the alternating current power supply and the load output are respectively connected to the circuit through different terminals, and are controlled to be connected by the first switch K1 and the second switch K2, so that the independent charging and discharging interface design is beneficial to independently designing the inductor group L2 in the charging loop, unnecessary loss caused by the load serving as a PWM converter in the inversion mode is avoided, and the efficiency of the system is improved. A secondary winding of the transformer T1 and a capacitor C2 form an LC filter which is used as an output filter in an inversion mode; the secondary winding of transformer T1 also forms an LCL filter with capacitor C2 and inductor L2 as the input filter in the charging mode. The transformer T1 plays a role of electrical isolation, provides electrical isolation for the battery at the DC side and the load at the AC side or the AC input power supply, improves the reliability of the system, and can effectively inhibit the transmission of electromagnetic interference.

In the embodiment of the present invention, the switch transistor of the PWM converter may be a semiconductor power device with a fully-controlled characteristic, such as an insulated gate bipolar transistor or a metal oxide field effect transistor. The automatic switch K4 may be a thyristor or a contactor.

It will be apparent to those skilled in the art that, for convenience and brevity of description, only the above-mentioned division of the functional units and modules is illustrated, and in practical applications, the above-mentioned function distribution may be performed by different functional units and modules according to needs, that is, the internal structure of the apparatus is divided into different functional units or modules to perform all or part of the above-mentioned functions.

The above-mentioned embodiments are only used for illustrating the technical solution of the present invention, and not for limiting the same; although the present invention has been described in detail with reference to the foregoing embodiments, it should be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; such modifications and substitutions do not substantially depart from the spirit and scope of the embodiments of the present invention, and are intended to be included within the scope of the present invention.

Claims

1. The utility model provides a integrative circuit of contravariant charges, the circuit is including the first binding post of connecting storage battery, the second binding post of connecting alternating current power supply to and the third binding post of connecting load, its characterized in that, the circuit still includes: the device comprises a direct current soft start module, a PWM converter, a transformer, a first switch and a second switch; the secondary side of the transformer is connected with the second connecting terminal through the first switch and is connected with the third connecting terminal through the second switch;

2. The charging and inverting integrated circuit of claim 1, wherein the dc soft start module comprises a contactor, a soft start resistor and a diode, and the soft start resistor and the diode are connected in series and then connected in parallel at two ends of the contactor, wherein a cathode of the diode is connected to the contactor, and an anode of the diode is connected to the soft start resistor.

3. The charging and inverting integrated circuit of claim 1, wherein the transformer is a single-phase transformer, and the circuit further comprises a fuse and an automatic switch connected in series in sequence to the live line on the secondary side of the transformer.

4. The charging and inverting integrated circuit of claim 3, wherein the PWM converter includes two phase legs, and each phase leg includes an upper leg switching tube and a lower leg switching tube.

5. The charging and inverting integrated circuit of claim 1, wherein the transformer is a three-phase transformer, the circuit further comprising a plurality of fuses and automatic switches connected in series in sequence on each phase line of the secondary side of the three-phase transformer.

6. The charging and inverting integrated circuit of claim 5, wherein the PWM converter includes three phase legs, and each phase leg includes an upper leg switching tube and a lower leg switching tube.

7. The charging and inverting integrated circuit of claim 1, further comprising a third switch connected to the first connection terminal, wherein one end of the third switch is connected to the front end of the dc soft start module, and the other end of the third switch is connected to the negative electrode of the first connection terminal.

8. The charging inversion integrated circuit as claimed in claim 1 or 2, wherein the circuit further comprises a first inductor and a first capacitor, the first inductor is connected between the positive electrode of the first connection terminal and the dc soft start module, one end of the first capacitor is connected to the output terminal of the dc soft start module, and the other end of the first capacitor is connected to the negative electrode of the first connection terminal.

9. The charging and inverting integrated circuit of claim 5 or 6, wherein the upper bridge arm switch tube and the lower bridge arm switch tube are insulated gate bipolar transistors or metal oxide field effect transistors.