CN104701836A - Intelligent direct-current micro-grid power supply system - Google Patents

Abstract

The invention discloses a DC microgrid intelligent power supply system, comprising a three-phase AC grid, a high power factor rectifier, a first isolated bidirectional DC conversion device, a second isolated bidirectional DC conversion device, a first DC bus, a second DC bus, microgrid energy dispatch management system, first control circuit, second control circuit, third control circuit, used to collect DC side voltage information, three-phase incoming line current information and three-phase incoming line voltage of three-phase AC power grid A first sampling and conditioning circuit for information, a second sampling and conditioning circuit for collecting current and voltage information on the high-voltage side and current and voltage information on the low-voltage side in the first isolated bidirectional DC conversion device, and a second sampling and conditioning circuit for collecting the second isolated type A second sampling and conditioning circuit for current and voltage information on the high-voltage side and current and voltage information on the low-voltage side in the bidirectional DC conversion device. The invention adopts the full-control rectification method to realize the bidirectional flow of energy and ensure the symmetry of the three-phase load of the power grid.

Description

A DC microgrid intelligent power supply system

technical field

The invention belongs to the field of new energy and relates to a power supply system, in particular to a DC microgrid intelligent power supply system.

Background technique

With the development of society and economy all over the world, people's demand for energy is increasing day by day. Energy conservation, environmental protection and sustainable development have become the themes of today's era. The development and utilization of new energy sources (wind energy, solar energy, etc.) has gradually become an effective way to meet people's load growth needs, reduce environmental pollution, improve energy comprehensive utilization efficiency and power supply reliability.

Due to the characteristics of poor stability, wide distribution, and complex system control of new energy, for large power grids, the distributed power generation system is an uncontrollable source, and the connection of a large number of distributed power sources to the large power grid will inevitably affect the stability of the large power grid. . When the large power grid fails, the distributed power grid needs to be disconnected from the power grid immediately to stop operation, which greatly limits the utilization rate of new energy.

With the popularization of digitalization, more and more civilian electrical appliances are digitalized, and most of the subsequent electrical equipment adopts DC power supply. In order to meet the power demand of DC loads and facilitate the access of distributed DC power sources to the main grid, DC microgrids have emerged as the times require. Unlike the AC microgrid, the bus voltage of the DC microgrid is DC, and there is no need to control the phase and frequency of the voltage. Therefore, the reliability and controllability of the microgrid are greatly improved. As an effective supplement to the traditional power grid, the DC microgrid can not only improve the power quality and meet the diverse needs of users, but also provide support for the power grid as a backup power source in emergency situations. The existing DC micro-grid adopts the method of uncontrolled rectification, which cannot realize the two-way flow of energy, and cannot solve the problem of power quality. Moreover, the power frequency transformer connected to the large power grid has a large volume, high cost, large floor space, and cannot Effectively ensure the symmetry of the three-phase load of the power grid, making the stability of the power grid lower.

Contents of the invention

The purpose of the present invention is to overcome the above-mentioned shortcomings of the prior art, and provide a DC microgrid intelligent power supply system, which can realize bidirectional energy flow and unit power factor rectification, and can ensure the symmetry of the three-phase load of the grid, while the volume Small and low cost.

To achieve the above purpose, the DC microgrid intelligent power supply system of the present invention includes a three-phase AC grid, a high power factor rectifier, a first isolated bidirectional DC converter, a second isolated bidirectional DC converter, a first DC bus , the second DC bus, the microgrid energy dispatch management system, the first control circuit, the second control circuit, and the third control circuit, used to collect the DC side voltage information of the three-phase AC grid, the three-phase incoming current information and the three-phase The first sampling and conditioning circuit for incoming line voltage information, the second sampling and conditioning circuit for collecting current and voltage information on the high-voltage side and the current and voltage information on the low-voltage side of the first isolated bidirectional DC conversion device, and a second sampling and conditioning circuit for collecting the first 2. A third sampling and conditioning circuit for current and voltage information on the high-voltage side and current and voltage information on the low-voltage side in the isolated bidirectional DC conversion device;

The three-phase AC grid is connected to the input end of the high power factor rectifier, and the output end of the high power factor rectifier is respectively connected to the first DC bus and the first isolated bidirectional DC conversion device and the second isolated bidirectional DC conversion device. The second DC bus is connected;

The microgrid energy dispatch management system is connected with the first control circuit, the second control circuit and the third control circuit, the output terminal of the first sampling conditioning circuit is connected with the input terminal of the first control circuit, and the The output terminal is connected to the control terminal of the high power factor rectifier, the output terminal of the second sampling conditioning circuit is connected to the input terminal of the second control circuit, and the output terminal of the second control circuit is connected to the control terminal of the first isolated bidirectional DC conversion device. The output terminal of the third sampling and conditioning circuit is connected with the input terminal of the third control circuit, and the output terminal of the third control circuit is connected with the control terminal of the second isolated bidirectional DC conversion device.

The three-phase AC grid is connected to the input end of the high power factor rectifier through the first protection and soft-start device.

The output end of the high power factor rectifier is connected to the first isolated bidirectional DC conversion device and the second isolated bidirectional DC conversion device through the second protection and soft start device and the third protection and soft start device respectively.

The first control circuit includes a first DSP chip and a first drive circuit, the output end of the first sampling conditioning circuit is connected with the input end of the first DSP chip, and the output end of the first DSP chip is connected to the high voltage through the first drive circuit. The control terminal of the power factor rectifier is connected.

The second control circuit includes a second DSP chip and a second drive circuit, the output end of the second sampling conditioning circuit is connected to the input end of the second DSP chip, and the output end of the second DSP chip is connected to the second drive circuit through the second drive circuit. The control terminals of an isolated bidirectional DC conversion device are connected to each other.

Described the 3rd control circuit comprises the 3rd DSP chip and the 3rd drive circuit, the output end of the 3rd sampling conditioning circuit is connected with the input end of the 3rd DSP chip, the output end of the 3rd DSP chip is connected with the 3rd drive circuit through the 3rd drive circuit. The control terminals of the two isolated bidirectional DC conversion devices are connected to each other.

The high power factor rectifier includes a three-phase filter and a three-phase fully-controlled bridge circuit, the first protection and soft-start device is connected to the input end of the three-phase filter, and the output end of the three-phase filter is connected to the three-phase fully-controlled bridge circuit. The input ends of the circuit are connected, the output ends of the three-phase full-controlled bridge circuit are respectively connected with the first isolated bidirectional DC conversion device and the second isolated bidirectional DC conversion device, and the input end of the first sampling conditioning circuit is connected with the three-phase filter The output terminal of the drive circuit is connected with the output terminal of the first drive circuit and the control terminal of the three-phase fully controlled bridge circuit.

The microgrid energy dispatch management system includes a hand-held intelligent terminal, an ARM control board and a host computer, the ARM control board and the control terminal of the first control circuit, the control terminal of the second control circuit, the control terminal of the third control circuit, the host computer machine and handheld smart terminal.

The voltage on the first DC bus is 48V, and the voltage on the second DC bus is 400V.

The DC side voltage information, three-phase incoming line current information and three-phase incoming line voltage information of the three-phase AC power grid are collected through the first sampling and conditioning circuit, and the first DSP chip is used for the DC side voltage information and three-phase incoming line voltage information of the three-phase AC power grid The current information and the three-phase incoming line voltage information are adjusted and AD converted, and the voltage phase of the three-phase AC grid is first locked through the phase-locked loop, and then the 3/2 conversion and conversion are performed sequentially based on the voltage phase of the three-phase AC grid. dq rotation transformation, in the dq coordinate system, the voltage outer loop PI calculation is first performed to obtain the current inner loop given value, and the current inner loop given value is subjected to the current inner loop PI calculation to obtain the high power factor rectifier (A) in the dq coordinates The given voltage value of the port under the system of dq, and then the given voltage value of the port of the high power factor rectifier (A) under the dq coordinate system is sequentially performed dq inverse transformation and 3/2 inverse transformation, and the abc coordinate system is obtained Port given voltage value, then SPWM modulation is performed on the given voltage value of the port under the abc coordinate system, and 6 channels of first pulse signals are generated by the ePWM module of the first DSP chip, and the first drive circuit is used for the 6 channels of first pulse signals The signal is amplified, and the switching tube of the high power factor rectifier is driven by the amplified 6-way first pulse signal, so that the three-phase incoming line current _ia , _ib , and _{ic are} sinusoidal, and are related to the voltage u of the three-phase AC grid _a , _ub , and _uc are in the same phase, so that the DC side voltage V _dc output by the high power factor rectifier remains constant and operates with a unit power factor.

The present invention has the following beneficial effects:

When the DC micro-grid intelligent power supply system described in the present invention is working, the voltage of the three-phase AC grid is rectified into a DC voltage through a high power factor rectifier, which can not only realize the energy transfer from AC to DC, but also realize the energy transfer from DC to AC grid. Energy feeding to meet the two-way flow of energy; through the first sampling and conditioning circuit to collect the DC side voltage information, three-phase incoming line current information and three-phase incoming line voltage information of the three-phase AC power grid, the first control circuit according to the three-phase AC The DC side voltage information of the power grid, the three-phase incoming line current information and the three-phase incoming line voltage information control the three-phase incoming line current into a three-phase sinusoidal current, and it is in phase with the voltage of the three-phase AC grid to achieve the purpose of improving power quality , no need to configure additional power quality control equipment, thereby saving equipment investment costs; at the same time, because the three-phase current at the input end of the high power factor rectifier can be controlled as a symmetrical component, it ensures the symmetry of the three-phase load of the power grid and reduces the imbalance of the power grid It is conducive to the safe and stable operation of the power system. In addition, the first isolated bidirectional DC conversion device and the second isolated bidirectional DC conversion device can not only realize the voltage conversion from DC to DC, but also realize the bidirectional flow of energy, and at the same time realize the electrical isolation of the large power grid and the DC bus. When transmitting the same power, the volume is smaller, the weight is lighter, and the cost is lower, which greatly reduces the system cost and system footprint, and improves the system economic benefits.

In addition, the voltage on the first DC bus is 48V, and the voltage on the second DC bus is 400V. The first DC bus can supply power to small power electrical equipment, such as mobile phone chargers, computer chargers, lamps and other equipment; The second DC bus can supply power to high-power electrical equipment, such as building elevators, high-power air conditioners, HVAC and other high-power equipment.

Description of drawings

Fig. 1 is a structural representation of the present invention;

Fig. 2 is the structural representation of the first control circuit, the second control circuit and the third control circuit in the present invention;

Fig. 3 is a structural schematic diagram of the first protection and soft-start device 01 in the present invention;

Fig. 4 is the structural representation of the high power factor rectifier control circuit D in the present invention;

Fig. 5 (a) the structural representation of the second protection and soft start device 04 in the present invention;

Fig. 5 (b) the structural representation of the third protection and soft start device 08 in the present invention;

6 is a schematic structural diagram of the first isolated bidirectional DC conversion device B in the present invention;

FIG. 7 is a schematic structural diagram of a second isolated bidirectional DC conversion device C in the present invention.

Among them, A is a high power factor rectifier, B is a first isolated bidirectional DC converter, C is a second isolated bidirectional DC converter, D is a high power factor rectifier control circuit, and E is a first isolated bidirectional DC converter Control circuit, F is the second isolated bidirectional DC converter control circuit, G is the microgrid energy dispatch management system, 01 is the first protection and soft start device, 02 is the three-phase filter, 03 is the three-phase full-control bridge circuit , 04 is the second protection and soft start device, 05 is the first DC filter inductor, 06 is the first bidirectional isolated DC converter, 07 is the first DC bus, 08 is the third protection and soft start device, 09 is The second DC filter inductor, 10 the second isolated bidirectional DC conversion device, 11 is the second DC bus, 001 is the first drive circuit, 002 is the first DSP chip, 003 is the first sampling conditioning circuit, 004 is the second driver circuit, 005 is the second DSP chip, 006 is the second sampling conditioning circuit, 007 is the third driving circuit, 008 is the third DSP chip, 009 is the third sampling conditioning circuit, 010 is the ARM control board, 011 is the handheld smart Terminal, 012 is the upper computer, 01a is the overcurrent protection device, 01b is the soft start device, 03b is the DC side capacitor, 04a is the first DC circuit breaker, 04b is the first fuse, 06a is the first high voltage side filter capacitor , 06b is the first high-voltage side single-phase fully-controlled bridge, 06c is the first high-frequency transformer, 06d is the first low-voltage side single-phase fully-controlled bridge, 06e is the first low-voltage side filter capacitor, 08a is the second DC circuit breaker, 08b is the second fuse, 10a is the second high-voltage side filter capacitor, 10b is the second high-voltage side single-phase full-control bridge, 10c is the second high-frequency transformer, 10d is the second low-voltage side single-phase full-control bridge, 10e is The second low voltage side filter capacitor.

Detailed ways

The present invention is described in further detail below in conjunction with accompanying drawing:

Referring to Fig. 1 and Fig. 2, the DC microgrid intelligent power supply system according to the present invention includes a three-phase AC grid, a high power factor rectifier A, a first isolated bidirectional DC converter B, a second isolated bidirectional DC converter C, The first DC bus 07, the second DC bus 11, the microgrid energy dispatch management system G, the first control circuit, the second control circuit, and the third control circuit are used to collect DC side voltage information of the three-phase AC grid, three The first sampling and conditioning circuit 003 for the phase incoming line current information and the three-phase incoming line voltage information, and the first sampling and conditioning circuit 003 for collecting the current and voltage information on the high voltage side and the current and voltage information on the low voltage side in the first isolated bidirectional DC conversion device B Two sampling and conditioning circuits 006, and a third sampling and conditioning circuit 009 for collecting the current and voltage information of the high-voltage side and the current and voltage information of the low-voltage side in the second isolated bidirectional DC conversion device C; the three-phase AC grid and the high-power The input terminals of the factor rectifier A are connected, and the output terminals of the high power factor rectifier A are respectively connected to the first DC bus 07 and the second DC bus through the first isolated bidirectional DC converter B and the second isolated bidirectional DC converter C 11-phase connection; the microgrid energy scheduling management system G is connected with the first control circuit, the second control circuit and the third control circuit, the output terminal of the first sampling conditioning circuit 003 is connected with the input terminal of the first control circuit, and the second The output terminal of a control circuit is connected to the control terminal of the high power factor rectifier A, the output terminal of the second sampling conditioning circuit 006 is connected to the input terminal of the second control circuit, and the output terminal of the second control circuit is connected to the first isolated type The control terminal of the bidirectional DC conversion device B is connected, the output terminal of the third sampling conditioning circuit 009 is connected with the input terminal of the third control circuit, and the output terminal of the third control circuit is connected with the control terminal of the second isolated bidirectional DC conversion device C. end connected.

It should be noted that the input end of the three-phase AC grid and the high power factor rectifier A is connected through the first protection and soft-start device 01; the output end of the high power factor rectifier A is respectively connected through the second protection and soft-start device 04 and the first Three protection and soft start devices 08 are connected with the first isolated bidirectional DC conversion device B and the second isolated bidirectional DC conversion device C; the first control circuit includes the first DSP chip 002 and the first drive circuit 001, the first sampling The output terminal of the conditioning circuit 003 is connected with the input terminal of the first DSP chip 002, and the output terminal of the first DSP chip 002 is connected with the control terminal of the high power factor rectifier A through the first driving circuit 001; the second control circuit includes the first Two DSP chips 005 and the second drive circuit 004, the output end of the second sampling conditioning circuit 006 is connected with the input end of the second DSP chip 005, the output end of the second DSP chip 005 is isolated from the first by the second drive circuit 004 The control end of the type bidirectional DC conversion device B is connected; the third control circuit includes a third DSP chip 008 and a third drive circuit 007, the output end of the third sampling conditioning circuit 009 is connected with the input end of the third DSP chip 008, The output end of the third DSP chip 008 is connected to the control end of the second isolated bidirectional DC conversion device C through the third drive circuit 007; the high power factor rectifier A includes a three-phase filter 02 and a three-phase fully controlled bridge circuit 03, The first protection and soft start device 01 are connected with the input end of the three-phase filter 02, the output end of the three-phase filter 02 is connected with the input end of the three-phase full-control bridge circuit 03, and the three-phase full-control bridge circuit 03 The output terminals are respectively connected to the first isolated bidirectional DC conversion device B and the second isolated bidirectional DC conversion device C, the input terminal of the first sampling conditioning circuit 003 is connected to the output terminal of the three-phase filter 02, and the first drive The output end of the circuit 001 is connected to the control end of the three-phase full-control bridge circuit 03; the microgrid energy dispatch management system G includes a hand-held intelligent terminal 011, an ARM control board 010 and a host computer 012, and the ARM control board 010 and the first control board The control terminal of the circuit, the control terminal of the second control circuit, the control terminal of the third control circuit, the host computer 012 and the hand-held intelligent terminal 011 are connected; the voltage on the first DC bus 07 is 48V, and the second DC bus 11 The voltage on it is 400V.

The first sampling and conditioning circuit 003 collects the DC side voltage information of the three-phase AC power grid, the three-phase incoming line current information and the three-phase incoming line voltage information, and the first DSP chip 002 collects the DC side voltage information of the three-phase AC power grid, the three-phase Incoming line current information and three-phase incoming line voltage information are adjusted and AD converted, and the voltage phase of the three-phase AC grid is first locked through the phase-locked loop, and then the voltage phase of the three-phase AC grid is used as a reference to perform 3/2 Transformation and dq rotation transformation, in the dq coordinate system, the voltage outer loop PI calculation is first performed to obtain the current inner loop given value, and the current inner loop given value is subjected to the current inner loop PI calculation to obtain the high power factor rectifier (A) in The given voltage value of the port under the system of dq coordinates, and then the given voltage value of the port of the high power factor rectifier (A) under the system of dq coordinates is subjected to dq inverse transformation and 3/2 inverse transformation in turn, to obtain the abc coordinates The given voltage value of the port under the system is then SPWM modulated to the given voltage value of the port under the abc coordinate system, and the ePWM module of the first DSP chip 002 generates 6 first pulse signals, and the first drive circuit 001 pairs 6 Amplify the first pulse signal of the 6 channels, and drive the switching tube of the high power factor rectifier A through the amplified 6 first pulse signals, so that the three-phase incoming current _ia , _ib , and _{ic are} sinusoidal, and are connected with the three-phase The voltages u _a , _ub , and u _c of the AC grid are in the same phase, so that the DC side voltage V _dc output by the high power factor rectifier A remains constant.

Referring to Fig. 3, the first protection and soft-start device 01 includes an overcurrent protection device 01a and a soft-start device 01b. At the moment of power-on, the small-capacity relay KM1 is first closed to allow the large power grid to charge the capacitor of the subsequent stage circuit, and then detects Whether the capacitor voltage reaches the set value, if it reaches the set value, then close the large-capacity relay KM2 and then disconnect KM1 to complete the system soft start.

With reference to Fig. 4, described high power factor rectifier A comprises three-phase filter 02, three-phase fully controlled bridge circuit 03 and DC side capacitor 03b, and three-phase filter 02 is the LCL filter that adopts; Three-phase fully controlled bridge circuit 03 The switch tube is an IGBT or MOSFET switch tube; the DC side capacitor 03b is an electrolytic capacitor;

The high power factor rectifier control circuit D includes a first sampling conditioning circuit 003, a first DSP chip 002, and a first driving circuit 001. First, through the first sampling conditioning circuit 003, the DC side voltage information of the three-phase AC grid, three Phase incoming current information and three-phase incoming line voltage information, the first DSP chip 002 adjusts and performs AD conversion on the DC side voltage information, three-phase incoming line current information and three-phase incoming line voltage information of the three-phase AC power grid, and First lock the voltage phase of the three-phase AC grid through the phase-locked loop, and then perform 3/2 transformation and dq rotation transformation sequentially based on the voltage phase of the three-phase AC grid, and first perform the voltage outer loop PI calculation in the dq coordinate system , to get the given value of the inner loop of the current, the given value of the inner loop of the current is subjected to the PI operation of the inner loop of the current to obtain the given voltage value of the port of the high power factor rectifier (A) under the system of dq coordinates, and then the high power The given voltage value of the factor rectifier (A) in the dq coordinate system performs dq inverse transformation and 3/2 inverse transformation sequentially, and then performs SPWM modulation on the given voltage value of the port in the abc coordinate system, and through the ePWM module of DSP Generate 6 channels of first pulse signals, the first drive circuit 001 amplifies the 6 channels of first pulse signals, and drives the switching tube of the high power factor rectifier A through the amplified 6 channels of first pulse signals, so that the three-phase The line current _ia , _ib , _ic is sinusoidal, and has the same phase with the voltage u _a , _ub , _uc of the three-phase AC grid to achieve the purpose of high power factor, so that the DC side voltage output by high power factor rectifier A _Vdc remains constant.

Referring to Fig. 5 (a), the first protection and soft start device 01 includes a first DC circuit breaker 04a and a first fuse 04b, and the first fuse 04b is used to limit the output current of the first DC bus 07 from passing large, so as to protect the high power factor rectifier A, the first DC circuit breaker 04a is used to control whether the first isolated bidirectional DC conversion device B is connected to the high power factor rectifier A, so as to control whether the operation of the low-voltage DC microgrid is in grid-connected mode or not Island mode.

Referring to FIG. 6, the first isolated bidirectional DC conversion device B includes a first bidirectional isolated DC converter 06 and a first DC filter inductor 05, and the first bidirectional isolated DC converter 06 includes a first high voltage side filter capacitor 06a, The first high-voltage side single-phase fully-controlled bridge 06b, the first high-frequency inductor, the first high-frequency transformer 06c, the first low-voltage side single-phase fully-controlled bridge 06d, and the first low-voltage side filter capacitor 06e, when working, the first high-voltage The side single-phase fully-controlled bridge 06b first inverts the high-voltage DC voltage into a high-voltage AC square wave voltage, and converts the high-voltage AC square wave into a low-voltage high-frequency square wave through the first high-frequency transformer 06c, and then passes through the first low-voltage side single-phase full-control bridge The control bridge 06d rectifies the low-voltage and high-frequency square wave into DC, realizes the conversion from DC to DC, and can realize the isolation of high-voltage DC and low-voltage DC.

The first DC bus 07 is used to connect low-voltage electrical equipment and low-voltage energy storage and power generation equipment, such as electric vehicle charging piles, various low-voltage household appliances, photovoltaic charging devices, battery energy storage devices, and the like.

With reference to Fig. 5 (b), described protective device 08 comprises the second DC circuit breaker 08a and the second fuse 08b, and the second fuse 08b is used for limiting the output current of the second DC bus 11 can not be too large, thereby protecting the front stage For the high power factor rectifier A, the second DC circuit breaker 08a is used to secondly control whether the isolated bidirectional DC conversion device C is connected to the high power factor rectifier A, so as to control the operation of the high-voltage DC microgrid and the grid-connected mode or the island mode.

Referring to FIG. 7, the second isolated bidirectional DC conversion device C includes a second DC filter inductor 09, a second high-voltage side filter capacitor 10a, a second high-voltage side single-phase full-controlled bridge 10b, a second high-frequency inductor, a second The high-frequency transformer 10c, the second low-voltage side single-phase full-control bridge 10d and the second low-voltage side filter capacitor 10e, first, the second high-voltage side single-phase full-control bridge 10b firstly inverts the high-voltage DC voltage into a high-voltage AC square wave voltage, The high-voltage AC square wave is transformed into a low-voltage high-frequency square wave through the second high-frequency transformer 10c, and then the low-voltage high-frequency square wave is rectified into DC through the second low-voltage side single-phase full-control bridge 10d to realize the conversion from DC to DC, and It can realize the isolation of high voltage DC and low voltage DC.

The second DC bus 11 is used to connect high-voltage electrical equipment with high-voltage energy storage and power generation equipment, such as building elevators, large-scale refrigeration equipment, high-power lighting equipment, and the like.

The first isolated bidirectional DC converter control circuit E includes a second DSP chip 005 , a second drive circuit 004 and a second sampling conditioning circuit 006 . Firstly, the current and voltage information of the high-voltage side and the current and voltage information of the low-voltage side in the first isolated bidirectional DC conversion device B are collected through the second sampling and conditioning circuit 006, and the current and voltage information of the high-voltage side of the first isolated bidirectional DC conversion device B are collected. The voltage information and the current and voltage information on the low voltage side are conditioned and input to the second DSP chip 005 after AD conversion, and the second DSP chip 005 is based on the current and voltage information on the high voltage side of the first isolated bidirectional DC converter B and the current and voltage information on the low-voltage side to obtain 8-way second pulse signals. After the 8-way second pulse signals are amplified, they drive the switch tube of the first isolated bidirectional DC conversion device B through the second drive circuit 004, so that the first The voltage of the DC bus 07 is stable.

The second isolated bidirectional DC converter control circuit F includes a DSP control board 008 , a driving circuit board 007 and a sampling conditioning module 009 . First, the high and low voltage side voltage and current of the isolated bidirectional DC converter are collected through the sampling conditioning module 009, and then sent to the AD sampling module of the first DSP chip 002 after conditioning, and then generated by the ePWM module of the first DSP chip 002 after relevant control operations The 8-way pulse signal is finally amplified by the driving circuit board 007 to drive the switch tube of the isolated bidirectional DC conversion device C, aiming to stabilize the voltage of the DC bus 11 .

The microgrid energy dispatch management system G includes an ARM control board 010010, a handheld intelligent terminal 011, and a host computer 012, which can issue control system start and stop commands through a PC, and can monitor the system operation in real time through the PC, and perform system Energy management, electricity bill metering, access to the system through the handheld smart terminal 011, call the system's operation status and electricity bill, which is convenient for users to use.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to the above embodiments, those of ordinary skill in the art should understand that the present invention can still be Any modification or equivalent replacement that does not depart from the spirit and scope of the present invention shall be covered by the scope of the claims of the present invention.

Claims (10)

1. A DC microgrid intelligent power supply system is characterized in that it comprises a three-phase AC grid, a high power factor rectifier (A), a first isolated type bidirectional DC conversion device (B), a second isolated type bidirectional DC conversion device ( C), the first DC bus (07), the second DC bus (11), the microgrid energy dispatch management system (G), the first control circuit, the second control circuit, the third control circuit, used to collect three-phase A first sampling and conditioning circuit (003) for the three-phase incoming line voltage information, three-phase incoming line current information, and DC side voltage information of the AC power grid, used to collect the current on the high voltage side of the first isolated bidirectional DC conversion device (B) and a second sampling and conditioning circuit (006) for voltage information and current and voltage information on the low-voltage side, and for collecting current and voltage information on the high-voltage side and current and voltage information on the low-voltage side in the second isolated bidirectional DC conversion device (C). A third sampling conditioning circuit (009) for voltage information; The three-phase AC grid is connected to the input end of the high power factor rectifier (A), and the output end of the high power factor rectifier (A) passes through the first isolated bidirectional DC conversion device (B) and the second isolated bidirectional DC converter (B) respectively. The conversion device (C) is connected to the first DC bus (07) and the second DC bus (11); The microgrid energy dispatch management system (G) is connected to the first control circuit, the second control circuit and the third control circuit, and the output terminal of the first sampling conditioning circuit (003) is connected to the input terminal of the first control circuit , the output terminal of the first control circuit is connected with the control terminal of the high power factor rectifier (A), the output terminal of the second sampling conditioning circuit (006) is connected with the input terminal of the second control circuit, and the output of the second control circuit terminal is connected with the control terminal of the first isolated bidirectional DC conversion device (B), the output terminal of the third sampling conditioning circuit (009) is connected with the input terminal of the third control circuit, and the output terminal of the third control circuit is connected with the first The control terminals of the two isolated bidirectional DC conversion devices (C) are connected to each other. 2. The DC microgrid intelligent power supply system according to claim 1, characterized in that, the input end of the three-phase AC grid and the high power factor rectifier (A) is connected through the first protection and soft start device (01) . 3. The DC micro-grid intelligent power supply system according to claim 2, characterized in that the output end of the high power factor rectifier (A) passes through the second protection and soft start device (04) and the third protection and soft start device (04) respectively. The starting device (08) is connected with the first isolated bidirectional DC conversion device (B) and the second isolated bidirectional DC conversion device (C). 4. The DC microgrid intelligent power supply system according to claim 1, characterized in that, the first control circuit comprises a first DSP chip (002) and a first drive circuit (001), a first sampling conditioning circuit (003 ) output end is connected with the input end of the first DSP chip (002), and the output end of the first DSP chip (002) is connected with the control end of the high power factor rectifier (A) through the first driving circuit (001). 5. The DC micro-grid intelligent power supply system according to claim 4, characterized in that, the second control circuit comprises a DSP chip (005) and a second drive circuit (004), a second sampling conditioning circuit (006) The output end of the second DSP chip (005) is connected to the input end of the first DSP chip (005), and the output end of the first DSP chip (005) is connected to the control end of the first isolated bidirectional DC conversion device (B) through the second drive circuit (004) . 6. The DC micro-grid intelligent power supply system according to claim 5, wherein the third control circuit includes a third DSP chip (008) and a third drive circuit (007), and a third sampling conditioning circuit (009 ) is connected to the input end of the third DSP chip (008), and the output end of the third DSP chip (008) is controlled by the third drive circuit (007) and the second isolated bidirectional DC converter (C) end connected. 7. The DC micro-grid intelligent power supply system according to claim 1, wherein the high power factor rectifier (A) comprises a three-phase filter (02) and a three-phase fully controlled bridge circuit (03), the first The protection and soft start device (01) is connected to the input end of the three-phase filter (02), and the output end of the three-phase filter (02) is connected to the input end of the three-phase fully controlled bridge circuit (03). The output end of the fully controlled bridge circuit (03) is respectively connected to the first isolated bidirectional DC conversion device (B) and the second isolated bidirectional DC conversion device (C), and the input end of the first sampling conditioning circuit (003) is connected to the The output ends of the three-phase filter (02) are connected, and the output end of the first drive circuit (001) is connected with the control end of the three-phase full-control bridge circuit (03). 8. The DC micro-grid intelligent power supply system according to claim 1, wherein the micro-grid energy dispatch management system (G) includes a hand-held intelligent terminal (011), an ARM control panel (010) and a host computer ( 012), the ARM control board (010) is connected with the control terminal of the first control circuit, the control terminal of the second control circuit, the control terminal of the third control circuit, the host computer (012) and the hand-held intelligent terminal (011). 9. The DC microgrid intelligent power supply system according to claim 1, characterized in that, the voltage on the first DC bus (07) is 48V, and the voltage on the second DC bus (11) is 400V. 10. The DC microgrid intelligent power supply system according to claim 4, characterized in that, the DC side voltage information of the three-phase AC grid, the three-phase incoming line current information and the three-phase incoming current information are collected by the first sampling conditioning circuit (003). Line voltage information, the first DSP chip (002) performs conditioning and AD conversion on the DC side voltage information, three-phase incoming line current information and three-phase incoming line voltage information of the three-phase AC grid, and first locks the three-phase through the phase-locked loop The voltage phase of the AC grid, and then take the voltage phase of the three-phase AC grid as a reference to perform 3/2 transformation and dq rotation transformation in sequence, and first perform the PI calculation of the voltage outer loop in the dq coordinate system to obtain the given value of the current inner loop , the given value of the current inner loop carries out the PI operation of the current inner loop to obtain the given voltage value of the port of the high power factor rectifier (A) in the dq coordinate system, and then the high power factor rectifier (A) in the dq coordinate The given voltage value of the port under the coordinate system is followed by dq inverse transformation and 3/2 inverse transformation to obtain the given voltage value of the port under the abc coordinate system, and then the SPWM modulation is performed on the given voltage value of the port under the abc coordinate system, and passed through the first The ePWM module of a DSP chip (002) generates 6-way first pulse signals, and the first drive circuit (001) amplifies the 6-way first pulse signals, and drives high-power pulse signals through the amplified 6-way first pulse signals The switching tube of the factor rectifier (A) makes the three-phase incoming current _ia , _ib , _ic sinusoidal, and makes the three-phase incoming current _ia , _ib , _ic and the voltage u _a of the three-phase AC grid , u _b , u _c are in the same phase, so that the DC side voltage V _dc output by the high power factor rectifier (A) remains constant and operates with a unit power factor.