CN210839321U

CN210839321U - 480V bidirectional energy storage converter

Info

Publication number: CN210839321U
Application number: CN201922054657.7U
Authority: CN
Inventors: 于海峰; 罗善喜; 陈华贵; 周磊; 袁伦; 李笑兰
Original assignee: Hubei Jiachenda New Energy Technology Co ltd
Current assignee: Hubei Jiachenda New Energy Technology Co ltd
Priority date: 2019-11-25
Filing date: 2019-11-25
Publication date: 2020-06-23
Anticipated expiration: 2029-11-25

Abstract

The utility model provides a 480V bidirectional energy storage converter, including two-way contravariant rectifier circuit and DSP module, still include the pulsation absorption circuit, the pulsation absorption circuit includes switch tube S1, diode D2, inductance L1 and electric capacity C2, the utility model discloses set up the pulsation absorption circuit, can eliminate the secondary pulsation of two-way contravariant rectifier circuit direct current side voltage, improved the power density of system and direct current output 'S stability, and the volume of pulsation absorption circuit is less, is favorable to 480V bidirectional energy storage converter' S miniaturized design and reduce cost.

Description

480V bidirectional energy storage converter

Technical Field

The utility model relates to a converter technical field especially relates to a 480V bidirectional energy storage converter.

Background

The bidirectional energy storage converter is a device for controlling energy to flow bidirectionally between an energy storage device and a direct current power grid, can be applied to various occasions such as a direct current micro-power grid, an electric automobile and the like, and a main circuit generally comprises a battery pack, a bidirectional inversion rectification circuit and a bidirectional DC/DC conversion circuit, wherein a 480V bidirectional energy storage converter is commonly used, the rated input voltage is 480V, and 40 batteries with the voltage of 12V can be selected to be connected in series to serve as a direct current source and the energy storage device.

In the 480V bidirectional energy storage converter, when the alternating current side of the bidirectional inversion rectifying circuit realizes unit power factor operation, secondary pulse power can be generated, and further secondary pulse occurs to direct current bus voltage.

SUMMERY OF THE UTILITY MODEL

In view of this, the utility model provides a 480V bidirectional energy storage converter to solve the problem that can produce secondary pulsating power, influence direct current side output voltage stability when two-way contravariant rectifier circuit interchange side realizes the unit power factor operation.

The technical scheme of the utility model is realized like this: the utility model provides a 480V bidirectional energy storage converter, including two-way contravariant rectifier circuit and DSP module, still include the pulsation absorption circuit, the pulsation absorption circuit includes switch tube S1, diode D2, inductance L1 and electric capacity C2, two-way contravariant rectifier circuit 'S the anodal input through switch tube S1, switch tube S1' S output, diode D2 'S negative pole, diode D2' S positive pole links to each other rather than the negative pole of direct current side in proper order, and switch tube S1, the public end of diode D2 negative pole link to each other through inductance L1, electric capacity C2 and diode D2 'S positive pole in proper order, switch tube S1' S control end with the DSP module links to each other.

Optionally, the pulsation absorbing circuit further includes a switching tube S2, the diode D2 is a body diode of the switching tube S2, an output end of the switching tube S1 is connected to a negative electrode of the dc side of the bidirectional inverter rectification circuit through an input end of the switching tube S2 and an output end of the switching tube S2, and a control end of the switching tube S2 is connected to the DSP module.

Optionally, the switching tube S1 and the switching tube S2 are both IGBTs.

Optionally, the 480V bidirectional energy storage converter further includes an impulse absorption circuit, and the impulse absorption circuit is connected to the impulse absorption circuit and is configured to absorb transient voltage and current.

Optionally, the impulse absorption circuit includes a resistor R1, a diode D3, an inductor L2, and a capacitor C3, a collector of the switching tube S1 is sequentially connected to an emitter of the switching tube S2 through an anode of a diode D3, a cathode of a diode D3, the inductor L2, and the capacitor C3, and the resistor R1 is connected in parallel to the diode D3.

Optionally, diode D3 is a fast recovery diode.

Optionally, the impulse absorption circuit includes a diode D4, a diode D5, a diode D6, a diode D7, a capacitor C4, a capacitor C5, a capacitor C6, and an inductor L3, a collector of the switching tube S1 sequentially passes through a positive electrode of the diode D4 and a negative electrode of the diode D4, the capacitor C4 is connected with the emitter of the switch tube S1, the collector of the switch tube S2 is connected with the emitter of the switch tube S2 through the capacitor C5, the anode of the diode D5 and the cathode of the diode D5 in sequence, the common end of the diode D4 and the capacitor C4 is connected with the DC side anode of the bidirectional inversion rectification circuit through the anode of the diode D6, the cathode of the diode D6 and the inductor L3 in sequence, the common end of the diode D5 and the capacitor C5 is connected with the DC side cathode of the bidirectional inversion rectification circuit through the cathode of the diode D7 and the anode of the diode D7, and the anode of the diode D6 is connected with the cathode of the diode D7 through the capacitor C6.

The utility model discloses a 480V bidirectional energy storage converter has following beneficial effect for prior art:

(1) the 480V bidirectional energy storage converter is provided with the pulsation absorption circuit, secondary pulsation of direct-current side voltage of the bidirectional inverter rectification circuit can be eliminated, the power density of a system and the stability of direct-current output are improved, and the volume of the pulsation absorption circuit is smaller, so that the 480V bidirectional energy storage converter is beneficial to miniaturization design and cost reduction;

(2) the utility model provides a diode D4, diode D5, diode D6, diode D7, electric capacity C4, electric capacity C5, electric capacity C6, the energy that the absorption circuit that inductance L3 constitutes stored can all transmit the load, have accomplished harmlessly approximately, are favorable to improving the efficiency of pulse absorption circuit.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, 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 creative efforts.

Fig. 1 is a block diagram of a 480V bidirectional energy storage converter according to the present invention;

fig. 2 is a circuit diagram of a ripple absorption circuit of the present invention;

fig. 3 is a circuit diagram of the pulsation absorbing circuit and the impulse absorbing circuit of the present invention;

fig. 4 is another circuit diagram of the pulsation absorbing circuit and the impulse absorbing circuit of the present invention.

Detailed Description

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

As shown in fig. 1, combine fig. 2, the utility model discloses a 480V bidirectional energy storage converter, including bidirectional inverter rectifier circuit, DSP module, pulsation absorption circuit includes switch tube S1, diode D2, inductance L1 and electric capacity C2, bidirectional inverter rectifier circuit ' S direct current side positive pole links to each other with its direct current side negative pole through switch tube S1 ' S input, switch tube S1 ' S output, diode D2 ' S negative pole, diode D2 ' S positive pole in proper order, and switch tube S1, the public end of diode D2 negative pole link to each other with diode D2 ' S positive pole through inductance L1, electric capacity C2 in proper order, switch tube S1 ' S control end with the DSP module links to each other.

In this embodiment, the 480V bidirectional energy storage converter further includes a 480V battery pack and a bidirectional DC/DC conversion circuit, the bidirectional DC/DC conversion circuit is a common non-isolated Buck-Boost voltage step-up and step-down conversion circuit, connection relationships and principles of the bidirectional DC/DC conversion circuit are not described herein, the bidirectional inverter rectification circuit is a common PWM three-phase fully-controlled rectifier bridge, the DSP module is configured to output PWM pulses to control duty ratios of respective switching tubes in the bidirectional DC/DC conversion circuit and the bidirectional inverter rectification circuit, and the capacitor C1 in fig. 2 is a DC bus capacitor of the bidirectional inverter rectification circuit.

When two-way contravariant rectifier circuit work is in the rectification state, can produce secondary pulsation power when its interchange side realizes that unit power factor moves in the time, and then lead to direct current bus voltage secondary pulsation to appear, to this problem, change electric capacity C1 for big electric capacity usually and restrain the low frequency ripple, the volume of big electric capacity is great, can make two-way contravariant rectifier circuit increase in volume, cost increase, the power density of system has been reduced to it is not a suitable selection to change electric capacity C1 for big electric capacity.

In this embodiment, a ripple absorption loop is arranged on the direct-current side of the bidirectional inverter rectification circuit, when secondary ripple occurs to the direct-current bus voltage, the DSP module detects the secondary ripple, at time t1, the DSP module controls the switching tube S1 to be turned on, the secondary ripple current flows through the inductor L1, the inductor L1 starts to charge energy, and simultaneously the capacitor C2 is charged, and the voltage at the two ends of the capacitor C2 is the superposition of the direct-current voltage and the secondary ripple voltage; at time t2, the DSP module will control the switch S1 to turn off, and the inductor L1 and the capacitor C2 discharge through the diode D2 to freewheel. When secondary pulsation occurs to the voltage of the direct current bus, the inductor L1 and the capacitor C2 are charged and discharged continuously, wherein the inductor L1 is a transfer element of the pulsating power, the capacitor C2 is an energy storage element of the pulsating power, and a compensation circuit formed by the switching tube S1, the inductor L1, the capacitor C2 and the diode D2 can compensate the secondary pulsating power generated by the system and eliminate the low-frequency pulsation of the voltage of the direct current bus. It is proved that if the amplitude and phase of the current of the capacitor C2 can be controlled correctly, the ripple power generated by the system can be eliminated by the compensation circuit under the condition that the power factor of the alternating current side is 1.

Therefore, the 480V bidirectional energy storage converter is provided with the pulsation absorption circuit, secondary pulsation of direct-current side voltage of the bidirectional inverter rectification circuit can be eliminated, the power density of a system and the stability of direct-current output are improved, the size of the pulsation absorption circuit is small, and the 480V bidirectional energy storage converter is beneficial to miniaturization design and cost reduction.

Optionally, as shown in fig. 3, the ripple absorbing circuit further includes a switching tube S2, the diode D2 is a body diode of the switching tube S2, an output end of the switching tube S1 is connected to a dc side negative electrode of the bidirectional inverter rectification circuit through an input end of the switching tube S2 and an output end of the switching tube S2, and a control end of the switching tube S2 is connected to the DSP module.

Generally, in a charging state of a conventional 480V battery pack, a battery current may have obvious oscillation in a period, an oscillation frequency is a multiple of a grid frequency, an oscillation amplitude of the battery current is related to an input power, and the oscillation amplitude may increase with an increase of the input power, so that low-frequency components in the battery current need to be compensated.

In this embodiment, the capacitor C2 may be a super capacitor, and the switching tube S1, the switching tube S2, the inductor L1, and the capacitor C2 form a circuit structure similar to a bidirectional DC/DC converter, and may be used to control the power of the system and compensate the low-frequency current component of the 480V battery pack by using the super capacitor as an energy storage unit.

Optionally, the switching tube S1 and the switching tube S2 are both IGBTs.

The switching tube S1 and the switching tube S2 may be IGBTs or MOS tubes, where the input end, the output end, and the control end of the switching tube are the collector, the emitter, and the gate of the IGBT, respectively, and the input end, the output end, and the control end of the switching tube are the drain, the source, and the gate of the MOS tube, respectively, when the switching tube is an MOS tube. The MOS tube is suitable for small current occasions, the IGBT is suitable for large current occasions, and the IGBT is preferably used in the embodiment and is applied to large current occasions.

Optionally, as shown in fig. 1, the 480V bidirectional energy storage converter further includes an impulse absorption circuit, and the impulse absorption circuit is connected to the impulse absorption circuit and is configured to absorb transient voltage and current.

Optionally, as shown in fig. 3, the impulse absorption circuit includes a resistor R1, a diode D3, an inductor L2, and a capacitor C3, a collector of the switching tube S1 is sequentially connected to an emitter of the switching tube S2 through an anode of a diode D3, a cathode of a diode D3, an inductor L2, and a capacitor C3, and the resistor R1 is connected in parallel to the diode D3.

Generally, during the turn-off process of the IGBT, the voltage peak appears at the collector of the IGBT due to the existence of the main loop stray inductance, which is the most serious condition when the IGBT is turned off by short circuit, and the voltage peak must be limited within the safe working area.

In this embodiment, for a single switch tube S1 or switch tube S2, the working process of the impulse absorption circuit is as follows: after the switch tube receives a turn-off signal, the bus current flowing through the parasitic inductor of the main loop is shunted through the switch tube and the impulse absorption circuit, the inductor L2 is charged, and the first peak voltage occurs in the process; after the switching tube is completely cut off, the energy stored in the inductor L2 is subjected to series resonance through the capacitor C3, the energy in the inductor L2 is released through the capacitor C3, and a second peak voltage occurs in the process; after the inductor L2 and the capacitor C3 finish series resonance, the capacitor C3 discharges through the resistor R1.

Thus, an impulse absorption circuit formed by the resistor R1, the diode D3, the inductor L2 and the capacitor C3 charges the capacitor C3 when the switching tube is turned off, energy stored in the capacitor C3 is fed back to the main circuit through the resistor R1, the voltage of the capacitor C3 is kept at a normal direct-current bus voltage, transient voltage in the circuit can be effectively suppressed, overvoltage of the collector of the switching tube is avoided, the switching tube is effectively protected, the resistor R1 can eliminate current oscillation caused by discharging of the capacitor C3, and the IGBT is in a stable state when being switched.

Optionally, diode D3 is a fast recovery diode. Generally, if the reverse recovery time of the diode D3 is long, the energy stored in the capacitor C3 may be directly applied to the collector of the switch tube, which may cause a breakdown of the switch tube. In this embodiment, the diode D3 is selected as a fast recovery diode, and the reverse recovery time is short, so that the energy stored in the capacitor C3 can be prevented from being directly loaded to the collector of the switching tube, and the protection of the switching tube is facilitated.

Optionally, as shown in fig. 4, the impulse absorption circuit includes a diode D4, a diode D5, a diode D6, a diode D7, a capacitor C4, a capacitor C5, a capacitor C6, an inductor L3, a collector of the switching tube S1 sequentially passes through a positive electrode of a diode D4 and a negative electrode of a diode D4, the capacitor C4 is connected with the emitter of the switch tube S1, the collector of the switch tube S2 is connected with the emitter of the switch tube S2 through the capacitor C5, the anode of the diode D5 and the cathode of the diode D5 in sequence, the common end of the diode D4 and the capacitor C4 is connected with the DC side anode of the bidirectional inversion rectification circuit through the anode of the diode D6, the cathode of the diode D6 and the inductor L3 in sequence, the common end of the diode D5 and the capacitor C5 is connected with the DC side cathode of the bidirectional inversion rectification circuit through the cathode of the diode D7 and the anode of the diode D7, and the anode of the diode D6 is connected with the cathode of the diode D7 through the capacitor C6.

The impulse absorption circuit formed by the resistor R1, the diode D3, the inductor L2 and the capacitor C3 is simple in structure and convenient to implement, but when the system power is further increased, the parasitic inductance of a loop is large, transient voltage and current cannot be effectively inhibited, and meanwhile the discharge time of the capacitor C3 is influenced by the existence of the resistor R1, so that the impulse absorption circuit has certain limitation.

In this embodiment, an absorption loop formed by the diode D4, the diode D5, the diode D6, the diode D7, the capacitor C4, the capacitor C5, the capacitor C6, and the inductor L3 has the following working process: at the first moment, the switching tube S1 is turned on, the load current (i.e., the current flowing to the pulse absorbing loop) is kept constant, and the voltage on the capacitor C4 is zero; at the second moment, the switch tube S1 is turned off, the switch tube S2 is turned on, and since the load current cannot suddenly change, the diode D4 is turned on, the capacitor C4 and the capacitor C6 are charged through the diode D4, and the capacitor C5 discharges; at the third moment, the capacitor C4 is charged to the output voltage of the bidirectional inverter rectification circuit, and the capacitor C5 discharges to zero; at the fourth moment, the energy of the parasitic inductor in the loop is transferred to the capacitor C6, the voltage of the capacitor C6 is larger than the output voltage of the bidirectional inverter rectification circuit, the energy stored in the capacitor C6 is fed back to the direct current side of the bidirectional inverter rectification circuit, and the diode D2 is in a conducting state; at the fifth moment, the switching tube S1 is turned on, the switching tube S2 is turned off, the capacitor C5 starts to be charged through the diode D5, the energy stored in the capacitor C4 is transferred to the capacitor C6, the energy is finally fed back to the bidirectional inverter rectification circuit through the inductor L3, the diode D6 and the diode D7, finally the capacitor C4 is discharged to zero, and the capacitor C5 is charged to the output voltage of the bidirectional inverter rectification circuit.

Therefore, energy stored in an absorption loop formed by the diode D4, the diode D5, the diode D6, the diode D7, the capacitor C4, the capacitor C5, the capacitor C6 and the inductor L3 can be completely transmitted to a load, the loss is approximately avoided, and the efficiency of the pulse absorption loop is improved.

The above description is only a preferred embodiment of the present invention, and should not be taken as limiting the invention, and any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A480V bidirectional energy storage converter comprises a bidirectional inverter rectification circuit and a DSP module, and is characterized by further comprising a pulsation absorption circuit, wherein the pulsation absorption circuit comprises a switching tube S1, a diode D2, an inductor L1 and a capacitor C2, the positive pole of the direct current side of the bidirectional inverter rectification circuit is sequentially connected with the negative pole of the direct current side of the bidirectional inverter rectification circuit through the input end of the switching tube S1, the output end of the switching tube S1, the negative pole of the diode D2 and the positive pole of the diode D2, the common ends of the switching tube S1 and the negative pole of the diode D2 are sequentially connected with the positive pole of the diode D2 through the inductor L1 and the capacitor C2, and the control end of the switching tube S1 is connected with the DSP module.

2. The 480V bidirectional energy storage converter as claimed in claim 1, wherein the ripple absorption circuit further comprises a switch tube S2, the diode D2 is a body diode of the switch tube S2, the output end of the switch tube S1 is connected to the negative electrode of the DC side of the bidirectional inverter rectification circuit through the input end of the switch tube S2 and the output end of the switch tube S2, and the control end of the switch tube S2 is connected to the DSP module.

3. The 480V bidirectional energy storage converter as claimed in claim 2, wherein the switch tube S1 and the switch tube S2 are IGBTs.

4. The 480V bidirectional energy storage converter according to claim 3, further comprising an impulse absorption circuit connected to said ripple absorption circuit for absorbing transient voltages and currents.

5. The 480V bidirectional energy storage converter as claimed in claim 4, wherein said impulse absorption circuit comprises a resistor R1, a diode D3, an inductor L2 and a capacitor C3, a collector of a switch tube S1 is connected with an emitter of a switch tube S2 through a positive electrode of a diode D3, a negative electrode of a diode D3, an inductor L2 and a capacitor C3 in sequence, and the resistor R1 is connected with a diode D3 in parallel.

6. The 480V bidirectional energy storage converter as claimed in claim 5, wherein the diode D3 is a fast recovery diode.

7. The 480V bidirectional energy storage converter as claimed in claim 4, wherein the impulse absorption circuit comprises a diode D4, a diode D5, a diode D6, a diode D7, a capacitor C4, a capacitor C5, a capacitor C6, and an inductor L3, a collector of a switching tube S1 is sequentially connected to an emitter of the switching tube S1 through a positive electrode of a diode D4, a negative electrode of a diode D4, and a capacitor C4, a collector of the switching tube S2 is sequentially connected to an emitter of the switching tube S2 through a capacitor C5, a positive electrode of a diode D5, and a negative electrode of a diode D5, a common terminal of a diode D4 and a capacitor C4 is sequentially connected to a positive electrode of a diode D6, a negative electrode of a diode D6, and a positive electrode of an inductor L3, a DC-side positive electrode of the bidirectional inverter rectifier circuit is connected to a common terminal of a diode D5 and a capacitor C5 through a negative electrode of a diode D7 and a positive electrode of a diode D7, the anode of the diode D6 is also connected to the cathode of the diode D7 via a capacitor C6.