CN102035382B - Single-magnetic core three-port direct current (DC) converters - Google Patents

Abstract

The invention discloses four kinds of single magnetic core three-port DC converters, belonging to the field of power electronic converters. The four kinds of converters are all composed of three switching tubes, three diodes, filter capacitors and filter inductors (or transformers), and are connected to the input source, battery and load, and the main power supply and battery can be realized simultaneously by using one converter. and power management of the load. Only one magnetic component is used in the converter of the present invention, which is small in size, light in weight, and high in power density. Each port is single-stage, which can effectively complete system power management and control, and is suitable for space satellite power supply and new energy power generation systems .

Description

Single Core Three-Port DC Converter

technical field

The invention relates to four kinds of single magnetic core three-port DC converters in power converters, and belongs to the field of power electronic converters.

Background technique

With the increasingly severe energy crisis and environmental pollution, new energy power generation technologies such as solar energy, wind energy, and fuel cells have become the focus of attention and research around the world. The independently operated new energy power generation system is a very important way for the application of new energy power generation. It can solve the problem of power supply in remote mountainous areas, isolated islands and other areas without power grids. In addition, space satellites generally use solar energy as an input source, and batteries As a backup power supply, it supplies power to the satellite together. This structure is consistent with the structure of the independent new energy power generation system. Therefore, the research on the independent new energy power generation system can be further promoted and applied to the space satellite power supply system and other fields.

The inherent defects of new energy power generation equipment have brought some new problems and challenges to the independent new energy power supply system, such as: the response speed of the fuel cell is relatively slow, and the output power cannot track the change of the load in time; Due to the influence of changes in natural conditions such as wind direction, sunlight intensity, and ambient temperature, it is impossible to continuously and stably output electric energy, resulting in an increase in system stability problems. Therefore, an independently operated new energy power generation system must be equipped with a certain capacity energy storage device. The energy storage device plays the role of energy balance and support, replenishing the short-term peak power of the system in time, recovering excess power, ensuring the continuity and reliability of power supply, improving the utilization rate of electric energy, and making the power generation equipment fluctuate in output power or load power When it is larger, it can still maintain good stability.

In an independent new energy power generation system that includes an energy storage link, since it is necessary to manage the power of the input source, the battery, and the load at the same time, it is generally necessary to use two or more converters to jointly complete the task of system power management, and the decentralized control of each converter , the system is large in size and weight, and there are multi-stage power conversions, so the system efficiency is low. In view of the above application background and existing problems, the researchers proposed to use a three-port converter instead of the above multiple independent converters to realize the power management of the independent new energy power generation system, such as the literature "Danwei Liu, Hui Li.A ZVS Bi-Directional DC -DC Converter for Multiple EnergyStorage Elements, IEEE Transactions on Power Electronics, 2006, vol.21(5): 1513-1517", literature "Chuanhong Zhao, Simon D.Round, Johann W.Kolar.An Isolated Three-Port BidirectionalDC- DC Converter With Decoupled Power Flow Management, IEEE Transactions on PowerElectronics, 2008, 23(5): 2443-2553" and the literature "Hariharan Krishnaswami, Ned Mohan.Three-PortSeries Resonant DC-DC Converter to Interface Renewable Energy Sourcesir g E With Energy Badid Storage Ports, IEEE Transactions on Power Electronics, 2009, 24(10): 2289-2297” proposed several different three-port converters, the common feature of which is that each port is isolated from each other through the transformer winding, so the ports are For isolation conversion, the number of switching tubes used is large, and the conversion efficiency will be affected.

Contents of the invention

Aiming at the deficiencies in the prior art, the present invention proposes four single-core three-port DC converters that can simultaneously realize the management and control of input source, storage battery and load power.

The structure of the first single magnetic core three-port DC converter includes: input source, battery, first to third switch tubes, first to third diodes, filter capacitor and filter inductor, wherein: the first diode The anode of the first diode is connected to the positive pole of the input source, the cathode of the first diode is respectively connected to the source of the third switching tube and one end of the filter inductor, and the other end of the filter inductor is respectively connected to the anode of the second diode, the third diode The anode of the diode and the drain of the first switch tube, the cathode of the second diode are respectively connected to one end of the filter capacitor and one end of the load, and the drain of the third switch tube is respectively connected to the positive pole of the storage battery and the source of the second switch tube, The drain of the second switching tube is connected to the cathode of the third diode, and the negative pole of the input source is respectively connected to the negative pole of the storage battery, the source of the first switching tube, the other end of the filter capacitor and the other end of the load.

The structure of the second single-core three-port DC converter includes: an input source, a battery, first to third switch tubes, first to third diodes, filter capacitors and filter inductors, wherein: the first switch tube The drain is connected to the anode of the input source, the source of the first switching tube is respectively connected to the source of the third switching tube, the cathode of the first diode and one end of the filter inductor, and the other end of the filter inductor is respectively connected to the third diode The anode of the second switch tube and the drain of the second switch tube, the source of the second switch tube are respectively connected to one end of the filter capacitor and one end of the load, the drain of the third switch tube is connected to the cathode of the second diode, and the second diode The anode of the input source is respectively connected to the positive pole of the battery and the cathode of the third diode, and the negative pole of the input source is respectively connected to the negative pole of the battery, the anode of the first diode, the other end of the filter capacitor and the other end of the load.

The structure of the third single-core three-port DC converter includes: input source, battery, first to third switch tubes, first to third diodes, filter capacitor and filter inductor, wherein: the first diode The anode of the first diode is connected to the anode of the input source, the cathode of the first diode is respectively connected to the source of the third switching tube, one end of the filter inductor and the cathode of the second diode, and the anode of the second diode is respectively connected to the filter capacitor One end and one end of the load, the drain of the third switching tube is connected to the positive pole of the battery and the source of the second switching tube, the drain of the second switching tube is connected to the cathode of the third diode, and the anode of the third diode The drain of the first switch tube, the other end of the filter inductor, the other end of the filter capacitor and the other end of the load are respectively connected, and the negative pole of the input source is respectively connected to the negative pole of the storage battery and the source pole of the first switch tube.

The structure of the fourth single-core three-port DC converter includes: an input source, a battery, first to third switch tubes, first to third diodes, a transformer and a filter capacitor, and the transformer includes a primary winding and a filter capacitor. The secondary winding, wherein: the anode of the first diode is connected to the anode of the input source, the cathode of the first diode is respectively connected to the source of the third switching tube and the terminal of the same name of the primary winding, and the drain of the third switching tube Connect the anode of the storage battery and the source of the second switching tube, the drain of the second switching tube is connected to the cathode of the third diode, and the anode of the third diode is respectively connected to the non-identical end of the primary winding and the first switch The drain of the tube and the negative pole of the input source are respectively connected to the negative pole of the battery and the source of the first switching tube, the non-identical end of the secondary winding is connected to the anode of the second diode, and the cathode of the second diode is respectively connected to the filter capacitor One end of the secondary winding and one end of the load, and the same end of the secondary winding are respectively connected to the other end of the filter capacitor and the other end of the load.

The present invention has following technical effect:

(1) The power management and control of the input source, battery and load are realized through a converter;

(2) The converter only uses one magnetic component, which is small in size, light in weight, high in power density and low in cost;

(3) There is a single stage between any two ports, and the system efficiency is high;

(4) The whole converter becomes a whole, adopts centralized control, simple control and high reliability.

Description of drawings

FIG. 1 is a schematic structural diagram of the first single magnetic core three-port DC converter of the present invention.

Fig. 2 is a structural principle diagram of the second type of single magnetic core three-port DC converter of the present invention.

Fig. 3 is a structural principle diagram of the third single-core three-port DC converter of the present invention.

FIG. 4 is a schematic structural diagram of a fourth single-core three-port DC converter of the present invention.

Figure 5(a) is the equivalent circuit diagram of the converter shown in Figure 1 working in dual-output mode; Figure 5(b) is the equivalent circuit diagram of the converter shown in Figure 1 working in dual-input mode; Figure 5 (c) is an equivalent circuit diagram when the converter shown in FIG. 1 works in a single-input single-output mode.

Symbol names in Figures 1 to 5: V _in is the input (DC) source; V _b is the battery; R _o is the load; T is the transformer; _NP is the primary winding of the transformer; N _S is the secondary winding of the transformer; S ₁ , S ₂ , S ₃ are the first, second, and third switch tubes; D ₁ , D ₂ , and D ₃ are the first, second, and third diodes; C _o is the filter capacitor; L _o is the filter inductor; v _Lo is the voltage across the filter inductor; i _Lo is the filter inductor current; V _o is the output voltage.

Detailed ways

The present invention will be further described below in conjunction with accompanying drawing.

As shown in Fig. 1, the first single-core three-port DC converter of the present invention includes an input source V _in , a storage battery V _b , first to third switching tubes S ₁ , S ₂ , S ₃ , first to third The third diode D ₁ , D ₂ , D ₃ , the filter capacitor C _o and the filter inductance L _o , wherein: the anode of the first diode D ₁ is connected to the anode of the input source V _in , and the first diode D ₁ The cathode of the third switch tube _S3 is connected to the source of the third switch S3 and one end of the filter inductor L _o , and the other end of the filter inductor L _o is respectively connected to the anode of the second diode _D2 , the anode of the third diode _D3 and The drain of the first switching tube _S1 and the cathode of the second diode _D2 are respectively connected to one end of the filter capacitor C _o and one end of the load R _o , and the drain of the third switching tube _S3 is respectively connected to the positive pole of the storage battery V _b and the source of the second switching tube _S2 , the drain of the second switching tube _S2 is connected to the cathode of the third diode _D3 , the negative pole of the input source V _in is respectively connected to the negative pole of the storage battery _Vb , the first switching tube S The source of ₁ , the other end of the filter capacitor C _o and the other end of the load R _o .

As shown in Figure 2, the second single-core three-port DC converter of the present invention includes an input source V _in , a storage battery V _b , first to third switch tubes S ₁ , S ₂ , S ₃ , first to third The third diode D ₁ , D ₂ , D ₃ , the filter capacitor C _o and the filter inductance L _o , wherein: the drain of the first switch S ₁ is connected to the anode of the input source V _in , and the drain of the first switch S ₁ The source is respectively connected to the source of the third switching tube _S3 , the cathode of the first diode _D1 and one end of the filter inductor L _o , and the other end of the filter inductor L _o is respectively connected to the anode of the third diode _D3 and The drain of the second switching tube _S2 , the source of the second switching tube _S2 are respectively connected to one end of the filter capacitor C _o and one end of the load R _o , and the drain of the third switching tube _S3 is connected to the second diode D ₂ , the anode of the second diode _D2 is respectively connected to the positive pole of the battery _Vb and the cathode of the third diode _D3 , and the negative pole of the input source _Vin is respectively connected to the negative pole of the battery _Vb , the first diode The anode of D ₁ , the other end of the filter capacitor C _o and the other end of the load R _o .

As shown in Figure 3, the third single-core three-port DC converter of the present invention includes an input source V _in , a storage battery V _b , first to third switch tubes S ₁ , S ₂ , S ₃ , first to third The third diode D ₁ , D ₂ , D ₃ , the filter capacitor C _o and the filter inductance L _o , wherein: the anode of the first diode D ₁ is connected to the anode of the input source V _in , and the first diode D ₁ The cathode of the third switch tube _S3 is connected to the source of the third switch, one end of the filter inductor L _o and the cathode of the second diode _D2 , and the anode of the second diode _D2 is respectively connected to one end of the filter capacitor C _o and the load One end of R _o , the drain of the third switching tube _S3 is respectively connected to the anode of the storage battery _Vb and the source of the second switching tube _S2 , and the drain of the second switching tube _S2 is connected to the third diode _D3 The cathode and the anode of the third diode _D3 are respectively connected to the drain of the first switching tube _S1 , the other end of the filter inductor L _o , the other end of the filter capacitor C _o and the other end of the load R _o , the input source V _in The negative pole of the battery _Vb is respectively connected to the negative pole of the battery Vb and the source pole of the first switching tube _S1 .

As shown in Figure 4, the fourth single-core three-port DC converter of the present invention includes an input source V _in , a storage battery V _b , first to third switching tubes S ₁ , S ₂ , S ₃ , first to third The third diode D ₁ , D ₂ , D ₃ , the transformer T and the filter capacitor C _o , the transformer T includes the primary winding _NP and the secondary winding _NS , wherein: the anode of the first diode D ₁ Connect the anode of the input source V _in , the cathode of the first diode _D1 is respectively connected to the source of the third switching tube _S3 and the terminal of the same name of the primary winding _NP , and the drain of the third switching tube _S3 is respectively connected to the storage battery The anode of _Vb and the source of the second switching tube _S2 , the drain of the second switching tube _S2 are connected to the cathode of the third diode _D3 , and the anodes of the third diode _D3 are respectively connected to the primary winding N The non-identical end of _P and the drain of the first switching tube _S1 , the negative pole of the input source V _in are respectively connected to the negative pole of the storage battery _Vb and the source of the first switching tube _S1 , and the non-identical end of the secondary winding _NS is connected to The anode of the second diode D ₂ and the cathode of the second diode D ₂ are respectively connected to one end of the filter capacitor C _o and one end of the load R _o , and the same-named ends of the secondary winding _NS are respectively connected to the other end of the filter capacitor C _o One end and the other end of the load R _o .

The first converter of the present invention is suitable for applications where the input source V _in voltage, the battery V _b voltage and the output voltage V _o of the load R _o meet V _in < V _b < V _o ; the second converter of the present invention It is suitable for applications where the input source V _in voltage, the storage battery V _b voltage and the output voltage V _o of the load R _o satisfy V _in > V _b > V _o ; the third and fourth converters of the present invention are suitable for the input source V _In the application where the voltage of in and the voltage of battery V _b satisfy V _in < V _b , there is no limit to the output voltage V _o of the load terminal R _o .

The specific working principle of the present invention will be described below by taking the single-core three-port DC converter shown in FIG. 1 as an example. The working principles of the other three single-core three-port DC converters are similar.

The converter shown in Figure 1 is suitable for an independent new energy power supply system. In this system, the input source V _in serves as the main energy source of the system to provide power to the load. When the power input by the input source V _in is greater than the power required by the load R _o , the excess power will charge the battery V _b , which is called the dual output mode; when the input power of the input source V _in is less than the required power of the load R _o When the power is low, the insufficient power is provided by the discharge of the battery V _b , which is called a dual-input mode; when the power input by the input source V _in is zero, the battery V _b supplies power to the load R _o alone, which is called this work mode It is a single input single output mode. The system can automatically select dual-input, dual-output or single-input-single-output mode to work according to the working state of the input source V _in and load R _o .

When the converter works in dual output mode, the third switch tube _S3 is always off, and the power of the system is managed by controlling the on and off of the first and second switch tubes _S1 and _S2 . The equivalent circuit of the converter As shown in Figure 5(a), the converter is equivalent to a dual-output Boost converter at this time.

When the converter works in dual-input mode, the second switching tube _S2 is always off, and the power of the system is managed by controlling the opening and closing of the first and third switching tubes _S1 and _S3 . The equivalent circuit of the converter As shown in Figure 5(b), the converter is equivalent to a dual-input Boost converter at this time.

When the converter works in the single-input single-output mode, the third switching tube _S3 is always on, and the second switching tube _S2 is always off, and the power of the system is managed by controlling the opening and closing of the first switching tube _S1 . The equivalent circuit of the converter is shown in Figure 5(c), and the converter is equivalent to a common Boost converter at this time.

The parameters of the specific embodiment of the converter shown in Figure 1 are listed below: the voltage of the input source V _in varies between 14 and 22V, the voltage of the storage battery V _b is 24V, the output voltage _Vo is 30V, and the power of the input source V _in It varies from 0 to 200W, and the power of the load R _o is constant at 140W. The first, second, and third switching tubes S ₁ , S ₂ , and S ₃ are all made of MOSFETs, and the switching frequency of the switching tubes is 80kHz. 2. The third diodes D ₁ , D ₂ , and D ₃ are all Schottky diodes.

Claims (4)

1. A single-core three-port DC converter, characterized in that it includes an input source (V _in ), a storage battery (V _b ), first to third switch tubes (S ₁ , S ₂ , S ₃ ), a second One to the third diode (D ₁ , D ₂ , D ₃ ), filter capacitor (C _o ) and filter inductor (L _o ), where: the anode of the first diode (D ₁ ) is connected to the input source (V _in ), the cathode of the first diode (D ₁ ) is respectively connected to the source of the third switch (S ₃ ) and one end of the filter inductor (L _o ), and the other end of the filter inductor (L _o ) is respectively connected to The anode of the second diode (D ₂ ), the anode of the third diode (D ₃ ) and the drain of the first switching tube (S ₁ ), and the cathode of the second diode (D ₂ ) are respectively connected to filter One end of the capacitor (C _o ) and one end of the load (R _o ), the drain of the third switch tube (S ₃ ) are respectively connected to the positive pole of the battery (V _b ) and the source of the second switch tube (S ₂ ). The drain of the second switching tube (S ₂ ) is connected to the cathode of the third diode (D ₃ ), the negative pole of the input source (V _in ) is respectively connected to the negative pole of the battery (V _b ) and the negative pole of the first switching tube (S ₁ ). Source, the other end of the filter capacitor (C _o ) and the other end of the load (R _o ); The input source (V _in ), the storage battery (V _b ) and the load (R _o ) respectively serve as one of the three ports. 2. A single-core three-port DC converter, characterized in that it includes an input source (V _in ), a storage battery (V _b ), first to third switch tubes (S ₁ , S ₂ , S ₃ ), a second One to the third diode (D ₁ , D ₂ , D ₃ ), filter capacitor (C _o ) and filter inductance (L _o ), where: the drain of the first switching tube (S ₁ ) is connected to the input source (V _in ), the source of the first switch (S ₁ ) is respectively connected to the source of the third switch (S ₃ ), the cathode of the first diode (D ₁ ) and one end of the filter inductor (L _o ) , the other end of the filter inductor (L _o ) is respectively connected to the anode of the third diode (D ₃ ) and the drain of the second switch (S ₂ ), and the source of the second switch (S ₂ ) is connected to the filter One end of the capacitor (C _o ) and one end of the load (R _o ), the drain of the third switch (S ₃ ) is connected to the cathode of the second diode (D ₂ ), the second diode (D ₂ ) The anode is respectively connected to the positive pole of the battery (V _b ) and the cathode of the third diode (D ₃ ), and the negative pole of the input source (V _in ) is respectively connected to the negative pole of the battery (V _b ), the first diode (D ₁ ) The anode of the filter capacitor (C _o ) and the other end of the load (R _o ); The input source (V _in ), the storage battery (V _b ) and the load (R _o ) respectively serve as one of the three ports. 3. A single-core three-port DC converter, characterized in that it includes an input source (V _in ), a storage battery (V _b ), first to third switch tubes (S ₁ , S ₂ , S ₃ ), a second One to the third diode (D ₁ , D ₂ , D ₃ ), filter capacitor (C _o ) and filter inductor (L _o ), where: the anode of the first diode (D ₁ ) is connected to the input source (V _in ), the cathode of the first diode (D ₁ ) is respectively connected to the source of the third switch (S ₃ ), one end of the filter inductor (L _o ) and the cathode of the second diode (D ₂ ) , the anode of the second diode (D ₂ ) is respectively connected to one end of the filter capacitor (C _o ) and one end of the load (R _o ), and the drain of the third switch tube (S ₃ ) is respectively connected to the battery (V _b ) The anode and the source of the second switch (S ₂ ), the drain of the second switch (S ₂ ) are connected to the cathode of the third diode (D ₃ ), and the anode of the third diode (D ₃ ) are respectively Connect the drain of the first switch (S ₁ ), the other end of the filter inductor (L _o ), the other end of the filter capacitor (C _o ) and the other end of the load (R _o ), and the negative pole of the input source (V _in ) Respectively connect the negative pole of the storage battery (V _b ) and the source pole of the first switching tube (S ₁ ); The input source (V _in ), the storage battery (V _b ) and the load (R _o ) respectively serve as one of the three ports. 4. A single-core three-port DC converter, characterized in that it includes an input source (V _in ), a storage battery (V _b ), first to third switch tubes (S ₁ , S ₂ , S ₃ ), a second One to the third diode (D ₁ , D ₂ , D ₃ ), transformer (T) and filter capacitor (C _o ), said transformer (T) includes primary winding ( _NP ) and secondary winding (N _S ), where: the anode of the first diode (D ₁ ) is connected to the anode of the input source (V _in ), and the cathode of the first diode (D ₁ ) is respectively connected to the source of the third switching tube (S ₃ ) The terminal with the same name as the primary winding ( _NP ), the drain of the third switching tube (S ₃ ) is respectively connected to the positive pole of the battery (V _b ) and the source of the second switching tube (S ₂ ), and the second switching tube ( The drain of S ₂ ) is connected to the cathode of the third diode (D ₃ ), and the anode of the third diode (D ₃ ) is respectively connected to the non-identical terminal of the primary winding ( _NP ) and the first switch tube (S ₁ ) the drain of the input source (V _in ) and the negative pole of the input source (V in ) are respectively connected to the negative pole of the storage battery (V _b ) and the source of the first switching tube (S ₁ ), and the non-identical end of the secondary winding ( _NS ) is connected to the second The anode of the diode (D ₂ ), the cathode of the second diode (D ₂ ) are respectively connected to one end of the filter capacitor (C _o ) and one end of the load (R _o ), and the same-named end of the secondary winding ( _NS ) Connect the other end of the filter capacitor (C _o ) and the other end of the load (R _o ) respectively; The input source (V _in ), the storage battery (V _b ) and the load (R _o ) respectively serve as one of the three ports.

Images