CN107565541A - A kind of distribution method of intelligent building direct-flow distribution system - Google Patents
A kind of distribution method of intelligent building direct-flow distribution system Download PDFInfo
- Publication number
- CN107565541A CN107565541A CN201610512903.7A CN201610512903A CN107565541A CN 107565541 A CN107565541 A CN 107565541A CN 201610512903 A CN201610512903 A CN 201610512903A CN 107565541 A CN107565541 A CN 107565541A
- Authority
- CN
- China
- Prior art keywords
- virtual
- mrow
- msub
- motor
- direct current
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Landscapes
- Control Of Ac Motors In General (AREA)
Abstract
本发明提供了一种智能建筑直流配电系统的配电方法，该直流配电系统包括配电变流器，直流母线，分布式能源，储能单元，负荷和接口变流器；所述配电变流器将交流电变为直流电后接入直流母线；分布式电源，储能单元和负荷通过接口变流器接入直流母线；所述方法包括：接口变流器融合虚拟电机控制和接口变流器自治控制。本发明提供的技术方案采用虚拟同步电机控制策略，直流接口变流器采用虚拟直流电机控制策略，变流器在控制上完美统一。虚拟电机的惯性和阻尼能提高直流配电系统应对扰动的能力。虚拟电机的外特性使得在直流配电系统的母线电压波动过程中，每台变流器按额定容量分担功率，提升了直流母线电压的稳定能力。
The invention provides a power distribution method for a DC power distribution system of an intelligent building. The DC power distribution system includes a power distribution converter, a DC bus, a distributed energy source, an energy storage unit, a load and an interface converter; The electric converter converts the alternating current into direct current and then connects to the direct current bus; the distributed power supply, the energy storage unit and the load are connected to the direct current bus through the interface converter; the method includes: the interface converter integrates the virtual motor control and the interface converter Streamer autonomous control. The technical scheme provided by the invention adopts a virtual synchronous motor control strategy, and the DC interface converter adopts a virtual DC motor control strategy, and the converters are perfectly unified in control. The inertia and damping of the virtual motor can improve the ability of the DC power distribution system to deal with disturbances. The external characteristics of the virtual motor make it possible for each converter to share the power according to the rated capacity during the bus voltage fluctuation of the DC power distribution system, which improves the stability of the DC bus voltage.
Description
Technical Field
The invention relates to a direct current power distribution system, in particular to a power distribution method of an intelligent building direct current power distribution system with distributed power sources and energy storage access.
Background
With the gradual exhaustion of petrochemical energy and the increasing concern of people on environmental pollution in the global scope, the intelligent building power supply scheme draws wide attention. Statistics shows that 70% of electric energy is consumed in the building, so that the significance of building energy saving is great. The green electric power operation mode gradually enables a new energy decentralized access mode taking a building as a carrier to be rapidly developed. For the alternating current distribution scheme, the direct current distribution scheme of intelligent building has more important meaning: the direct current distribution can avoid the specific electric energy quality problems of reactive power, harmonic wave and the like of the traditional alternating current system. A large number of distributed power supplies and loads are in a direct current form, and a redundant AC/DC converter link can be omitted by adopting direct current distribution, so that the cost and the loss of a power distribution system are reduced, and the efficiency and the reliability are improved. When equipment mounted on a direct-current bus of a direct-current power distribution system is put into or cut off, disturbance of the direct-current bus can be caused, and the fluctuation of the power of the mounted equipment can also cause disturbance of the direct-current bus, so that the voltage stability of the direct-current bus is reduced. There is therefore a need to provide a solution to the needs of the prior art.
Disclosure of Invention
The technical problem to be solved by the invention is to provide a power distribution method of an intelligent building direct current power distribution system, which improves the disturbance resistance capability of the direct current power distribution system and improves the stability of direct current bus voltage through a virtual motor.
In order to achieve the purpose, the technical scheme adopted by the invention is as follows:
a power distribution method of an intelligent building direct current power distribution system comprises a power distribution converter, a direct current bus, distributed energy, an energy storage unit, a load and interface converter; the distribution converter is connected to a direct current bus after converting alternating current into direct current; the distributed power supply, the energy storage unit and the load are connected to the direct current bus through the interface converter; the method comprises the following steps:
1) the interface converter is integrated with virtual motor control;
2) the interface converter is controlled autonomously;
the interface converter includes: an AC/DC converter, a DC/DC converter, and a DC/AC inverter, the virtual machine control comprising: virtual synchronous motor control and virtual direct current motor control.
The AC/DC converter and the DC/AC inverter are controlled by a virtual synchronous motor in a fusion way, and the DC/DC converter is controlled by a virtual direct current motor.
The virtual synchronous motor control includes:
1) determining a mechanical equation for the virtual synchronous machine represented by:
wherein J is the rotational inertia of the virtual motor and has the unit of kg.m2(ii) a When the number of pole pairs is 1, the mechanical angular velocity ω of the virtual synchronous motor is the electrical angular velocity, ω being0The unit is rad/s for the synchronous angular speed of the power grid; t ism、TeAnd TdRespectively the mechanical torque, the electromagnetic torque and the damping torque of the virtual synchronous motor, and the unit is N.m; d is a damping coefficient with the unit of N.m.s/rad;
the electromagnetic torque TeAs shown in the following formula:
Te＝Pe/ω＝(eaia+ebib+ecic)/ω，
wherein e isabcTo virtual motor potential, iabcFor outputting current, P, to a virtual motoreElectromagnetic power output for the virtual motor;
2) determining an electromagnetic equation of the virtual synchronous machine as shown in the following formula:
wherein L is virtual synchronizationSynchronous inductance of the motor, R is the synchronous resistance of the virtual synchronous motor, uabcIs the terminal voltage of the virtual synchronous motor;
3) adjusting an active instruction of the virtual synchronous motor:
adjusting mechanical torque T of a virtual synchronous machinemTo realize the regulation of the active command of the virtual synchronous machine, said mechanical torque TmComprising a mechanical torque command T0And a frequency deviation feedback command Δ T;
the mechanical torque command T0As shown in the following formula:
T0＝Pref/ω，
wherein, PrefAn active instruction of the virtual synchronous motor;
the frequency deviation feedback command Δ T is expressed as follows:
ΔT＝-kf(f-f0)，
wherein f is the frequency of the terminal voltage of the virtual synchronous motor, f0For the grid reference frequency, kfIs a frequency modulation coefficient;
4) adjusting the terminal voltage and the reactive power of the virtual synchronous motor:
adjusting the virtual electric potential E of the virtual synchronous motor to adjust the terminal voltage and the reactive power of the virtual synchronous motor;
the virtual potential E is represented by the following equation:
E＝E0+ΔEQ+ΔEU，
wherein E is0Is the no-load potential of the virtual synchronous motor, the terminal voltage when the no-load is running off the network; delta EQIs the potential of the reactive power part; delta EUIs the output potential of the terminal voltage regulating unit;
potential deltae of the reactive power sectionQThe following formulaShown in the figure:
ΔEQ＝kq(Qref-Q)，
wherein k isqTo adjust the coefficient of reactive power, QrefFor the reactive instruction, the instantaneous reactive power Q output by the terminal is as follows:
output potential delta E of terminal voltage regulation unitUAs shown in the following formula:
ΔEU＝kv(Uref-U)，
wherein k isvFor regulating the coefficient of voltage, UrefAnd U is the instruction value and the true value of the effective value of the terminal voltage respectively;
the virtual synchronous motor virtual potential E voltage vector is shown as follows:
wherein,is the phase of the virtual synchronous machine.
The virtual direct current motor control comprises:
1) determining a mechanical equation of the virtual DC motor represented by:
Tm＝Pe/ω＝EI/ω，
wherein: j is the rotational inertia of the virtual motor; d is a damping coefficient; t ism、TeAre respectively provided withMechanical torque and electromagnetic torque of the virtual motor are obtained; omega is mechanical angular velocity; omega0Synchronizing the angular speed for the grid; peElectromagnetic power output for the virtual motor; e is a virtual potential, and I is a virtual current;
2) determining an electrical equation of the virtual DC motor as shown in the following formula:
E＝CTφω，
E＝U+IRa，
e is a virtual potential; i is a virtual current; cTIs a torque coefficient; u is terminal voltage; raIs the equivalent resistance of the armature; phi is the magnetic flux and omega is the mechanical angular velocity.
The interface converter autonomous control comprises: and the load electricity utilization information acquired by the interface converter is subjected to feedback regulation control.
The distributed energy source comprises: wind power generators and photovoltaic panels.
The energy storage unit includes: super capacitor and battery.
The load includes: DC load and AC load
Compared with the closest prior art, the technical scheme provided by the invention has the following beneficial effects:
1. most loads and distributed power supplies can use or provide electric energy in a direct current form, and compared with alternating current distribution, a large number of AC/DC converter modules are simplified, so that the system is compact, efficient and low in cost.
2. The AC interface converter adopts a virtual synchronous motor control strategy, the DC interface converter adopts a virtual DC motor control strategy, and the converters are perfectly unified in control.
3. The inertia and damping of the virtual motor can improve the disturbance handling capacity of the direct current power distribution system.
4. The external characteristics of the virtual motor enable each converter to share power according to rated capacity in the bus voltage fluctuation process of the direct current power distribution system, and stability of direct current bus voltage is improved.
Drawings
FIG. 1 is a schematic diagram of a DC power distribution system;
FIG. 2 is a schematic diagram of the duality of the AC/DC converter and the synchronous motor;
FIG. 3 is a schematic diagram of the duality of a DC/AC inverter and a synchronous generator;
FIG. 4 is a schematic structural diagram of the uniformity of a virtual synchronous motor;
FIG. 5 is an equivalent alternative schematic diagram of a virtual synchronous machine;
FIG. 6 is a circuit diagram of a virtual synchronous motor control circuit;
FIG. 7 is a schematic diagram of a virtual DC motor;
FIG. 8 is a virtual DC motor control circuit diagram;
FIG. 9 is a schematic structural diagram of autonomous control of a virtual motor;
FIG. 10 is a schematic diagram of the dynamic response of the DC bus voltage;
FIG. 11 is a schematic diagram of the dynamic response of an AC mains distribution converter;
FIG. 12 is a schematic diagram of the dynamic response of virtual potentials and angular velocities;
FIG. 13 is a schematic diagram of the dynamic response of the output power of a photovoltaic cell system;
FIG. 14 is a schematic view of the dynamic response of the output power of the wind turbine;
FIG. 15 is a schematic diagram showing the dynamic response of the voltage at the output of the DC load;
fig. 16 is a diagram illustrating the dynamic response of load power.
Detailed Description
The following describes embodiments of the present invention in further detail with reference to the accompanying drawings.
The invention provides a power distribution method of an intelligent building direct-current power distribution system based on a virtual motor technology. As shown in fig. 1, the power distribution system is formed by networking a plurality of parts, such as a power distribution converter, a direct current bus, distributed energy, an energy storage unit, a load, and an interface converter required by each unit. After the single-phase alternating current of the power grid is converted into direct current through the distribution converter, the direct current is connected to a 400V direct current bus and is connected with various distributed power supplies, energy storage units and loads in a building. The distributed power supply comprises a wind driven generator and a roof photovoltaic panel; the energy storage comprises a super capacitor and a storage battery; the loads include home appliances such as televisions, air conditioners, refrigerators, washing machines, and computers. The distributed power supply, the energy storage unit and the load are connected into the direct current bus through the interface converter.
The power distribution method comprises the following steps:
1. virtual motor control method for direct current bus interface converter
Interface converters such as an AC/DC converter, a DC/DC converter and a DC/AC inverter on a direct current bus are fused with virtual motor control. Specifically, an AC/DC converter and an interface of a power grid are fused with virtual synchronous motor control, distributed energy sources, energy storage and direct current loads are connected to a direct current bus through the DC/DC converter which is fused with the virtual direct current motor control, and alternating current loads are connected to the direct current bus through a three-phase or single-phase DC/AC inverter which is fused with the virtual synchronous motor control. And forming an intelligent building direct-current power distribution system based on the virtual motor technology.
1) Virtual synchronous motor control method
From the flow direction of the energy exchange between the alternating current system and the direct current system: the AC/DC converter has duality with the synchronous motor when absorbing power, as shown in FIG. 2; there is duality with the synchronous generator when the DC/AC inverter is generating power, as shown in fig. 3; since the synchronous generator and the synchronous motor have uniformity, the control strategy of the AC/DC converter or the DC/AC inverter has uniformity and uniformly shows a virtual synchronous motor characteristic, as shown in FIG. 4.
Further, the purpose of the virtual synchronous machine control of the ac and dc bus interface is to make the interface equivalent to a synchronous machine as shown in fig. 5.
According to the characteristics of the synchronous motor, the mechanical equation of the virtual synchronous motor is shown as follows:
wherein J is the rotational inertia of the virtual motor and has the unit of kg.m2(ii) a When the number of pole pairs is 1, the mechanical angular velocity ω of the virtual synchronous motor is the electrical angular velocity, ω being0The unit is rad/s for the synchronous angular speed of the power grid; t ism、TeAnd TdRespectively the mechanical torque, the electromagnetic torque and the damping torque of the virtual synchronous generator, and the unit is N.m; d is damping coefficient with the unit of N.m.s/rad. Wherein, the motor electromagnetic torque TeCan be controlled by a virtual motor potential eabcAnd a virtual motor output current iabcIs calculated to obtain
Te＝Pe/ω＝(eaia+ebib+ecic)/ω (2)
Wherein e isabcAnd iabcRespectively have the units V and A, PeThe electromagnetic power output for the virtual motor.
From FIG. 5, the electromagnetic equation of the virtual synchronous machine can be obtained as
Wherein L is the synchronous inductance of the virtual synchronous motor, R is the synchronous resistance of the virtual synchronous motor, uabcIs the terminal voltage of the virtual synchronous motor.
The traditional synchronous motor adjusts the active output of the motor through adjusting the mechanical torque, and realizes the response to the frequency deviation of the power grid through a frequency modulator. By mechanical torque T to the virtual synchronous machinemThe regulation of the inverter active command is realized. T ismFrom mechanical torque command T0And a frequency deviation feedback command delta T, wherein T0Can be expressed as
T0＝Pref/ω (4)
Wherein, PrefIs an active command of the virtual synchronous motor.
ΔT＝-kf(f-f0) (5)
Wherein f is the frequency of the terminal voltage of the virtual synchronous motor, f0For the grid reference frequency, kfIs the frequency modulation coefficient.
The synchronous motor adjusts the reactive output and the terminal voltage thereof by adjusting excitation. The terminal voltage and the reactive power can be adjusted by adjusting the virtual potential E of the virtual synchronous machine.
The virtual potential E of a virtual synchronous machine consists of three parts, which can be represented as
E＝E0+ΔEQ+ΔEU(6)
One is the no-load potential E of the virtual synchronous motor0And the terminal voltage of the inverter in no-load off-grid operation is represented.
Second, is the fraction Δ E corresponding to reactive power regulationQCan be expressed as
ΔEQ＝kq(Qref-Q) (7)
Wherein k isqTo adjust the coefficient of reactive power, QrefFor the reactive instruction of the grid-connected inverter, Q is the instantaneous reactive power value output by the inverter terminal, and can be expressed as
Thirdly, corresponding to the output delta E of the terminal voltage regulation unitUEquivalent to the output of an excitation Regulator or an Automatic Voltage Regulator (AVR) of a synchronous motor, the AVR is simplified to a proportional element, Δ EUCan be expressed as
ΔEU＝kv(Uref-U) (9)
Wherein k isvFor regulating the coefficient of voltage, UrefAnd U is respectively an instruction value and a true value of the effective value of the bridge arm voltage of the converter.
Further, a virtual synchronous motor potential voltage vector can be obtained
Wherein,is the phase of the virtual synchronous generator.
As can be seen from the formulas (1) to (10), the virtual synchronous motor can also adjust the frequency and support the voltage of the alternating current network on the basis of meeting the requirement of power transmission.
The virtual synchronous motor control strategy of the ac system and the dc system shown in fig. 6 can be obtained by equations (1) to (10).
2) Control method of virtual direct current motor
From the perspective of bidirectional flow of energy of a direct current system, the direct current generator and the direct current motor have uniformity, so that a control strategy of the DC/DC converter has uniformity, the uniformity is expressed as the characteristic of a virtual direct current motor, a dual relation between a mechanical equation and an armature equation of the direct current motor and a port network of the DC/DC converter is obtained, and the principle of the virtual direct current motor is shown in FIG. 7.
The direct current motor comprises an electrical part and a mechanical part:
mechanical equation:
Tm＝Pe/ω＝EI/ω， (12)
wherein: j is the rotational inertia of the virtual motor; d is a damping coefficient; t ism、TeRespectively the mechanical torque and the electromagnetic torque of the virtual motor; omega is mechanical angular velocity; omega0Synchronizing the angular speed for the grid; peElectromagnetic power output for the virtual motor; e is a virtual potential, and I is a virtual current;
as can be seen from equations (11) and (12), the virtual electromagnetic torque of the dc motor is braking in nature with respect to the virtual mechanical torque provided by the dc bus voltage. When the power is balanced, the voltage can be kept stable without power exchange on the bus voltage, and the DC/DC converter and the bus voltage cause the change of the induced potential and the armature end voltage, namely the change of the load end voltage. And the mechanical torque can provide inertia, so that the direct current converter and the bus are flexibly combined, and a buffer is provided for the fluctuation of the bus voltage.
Electrical equation:
E＝CTφω， (13)
E＝U+IRa， (14)
e is a virtual potential; i is a virtual current; cTIs a torque coefficient; u is terminal voltage; raIs the equivalent resistance of the armature; phi is the magnetic flux and omega is the mechanical angular velocity.
As can be seen from the equation (13), at a certain time of the exciting current, the potential is in direct proportion to the angular speed, and the invention adjusts the actual angular speed according to the mechanical equation of the direct current generator, so as to adjust the potential E and keep the potential stable, thereby ensuring that the voltage at the output end is unchanged, namely maintaining the voltage at the load end to be balanced.
The control strategy of the DC/DC converter fusion virtual direct current motor shown in FIG. 8 can be obtained through the formulas (11) to (14), wherein IrefThe reference value of the direct current side current of the DC/DC converter is calculated through a virtual direct current motor control strategy; i is1Is the load side current of the actual DC/DC converter; u shape2refIs a load side voltage reference value, U2The actual value of the voltage on the load side is obtained; d is a damping coefficient; omega is the actual angular velocity; omega0Is the nominal angular velocity.
Through the virtual direct current motor control strategy shown in fig. 8, the output end U of the two ports can be enabled1-I1Or (U)2-I2) The external characteristics of the magnetic field generator are consistent with those of a direct current motor.
The virtual motor control strategy can actively control the power absorbed by the load from the bus, effectively support the voltage recovery of the bus and maintain the voltage stability; when the bus voltage is disturbed and the voltage on the load side is stabilized to the rated value when the voltage drops, the voltage recovery process is a moderate oscillation process. The virtual direct current generator control strategy is a robust and flexible direct current converter control method, the control system can maintain the direct current bus voltage unchanged at a rated value, the stable operation of a direct current distribution network is ensured, and voltage impact cannot be generated to influence the load operation when the load voltage is disturbed and restored to the stable value.
2. Autonomous control method of interface converter
When equipment mounted on the direct-current bus is thrown or cut off, the direct-current bus voltage has small-range fluctuation and sudden change, and the stability of the direct-current bus voltage can be improved by using the damping and inertia of the virtual motor.
As shown in fig. 9, the interface converter in the dc power distribution system integrates a control strategy of a virtual motor in a local controller, the converters are coupled by public information (dc bus voltage, grid voltage, and frequency), the converter only needs to collect the local information to perform feedback regulation control, and each converter unit can operate independently and autonomously.
In the fluctuation process of the DC bus voltage, the voltage deviation delta U of the DC bus can be obtaineddcFor an AC network the transfer function between the exchange power deviations Δ P is
The steady state power response is
Therefore, in the process of voltage disturbance of the direct current bus, the power sharing capacity of the virtual synchronous motor is related to the proportionality coefficient of the PI controller.
For virtual DC motors, there are
As can be seen from equations (15) - (16), the converter interface controlled by the virtual motor has different damping parameters D due to different rated powers, and the power response in the fluctuation process of the dc bus voltage is shared according to the rated power and is inversely proportional to the damping parameter D.
The specific embodiment is as follows:
as with the dc distribution scheme shown in fig. 1, the system operates as follows: 2s illumination is stepped from 800W/m2 to 1200W/m 2; 4s wind speed is stepped from 6m/s to 5 m/s; inputting a load of 50 omega into the 6s direct current bus; the 8s AC load increased from 6kW/1.5kvar to 9kW/1.5 kvar.
(1) Direct current bus under control of virtual motor
As shown in fig. 10, the dynamic response of the dc bus voltage is:
besides the larger impact when the bus is charged from zero voltage to rated voltage, the system has good inhibition capability on other disturbances such as load switching, new energy output fluctuation and the like so as to maintain the stability of the voltage of the direct current bus.
(2) Distribution converter under control of virtual synchronous motor
As shown in fig. 11, the dynamic response of the ac grid distribution converter:
because the reactive power instruction for controlling the distribution converter is zero, no reactive power is exchanged between the distribution converter and the power grid. However, to maintain the dc bus voltage stable and to power the dc loads within the smart building, the incoming converter will claim active power from the grid.
The virtual potential Ep and the angular velocity ω are shown in fig. 12.
Under the action of a virtual synchronous motor control strategy, the virtual electromagnetic torque can well track the given mechanical torque, and the good active power tracking performance of the grid-connected converter is reflected.
Since the converter is drawing active power from the grid, the virtual potential Ep of the virtual synchronous generator is lower than the peak 311V of the grid phase voltage. While the rotational speed of the virtual synchronous generator can be maintained at 314rad/s synchronous to the grid. It is worth pointing out that: because the control of the voltage of the direct current bus is introduced into the controller as the given of the active instruction of the converter, the virtual potential and the angular speed of the converter are mutually coupled with disturbance events such as load switching on the direct current bus, output fluctuation of a distributed power supply and the like.
(3) Photovoltaic cell
As shown in fig. 13, the output power P after the maximum power tracking control of the photovoltaic panel:
the photovoltaic cell panel works in a mode of maximum power output, the output power is increased in 2s, and the maximum utilization of renewable energy sources is realized.
(3) Wind power generator
As shown in fig. 14, the response condition of the low-power permanent magnet direct-drive wind turbine is as follows:
when the wind speed is reduced, the machine end voltage of the fan is reduced, less power is fed to a power grid, and the dynamic state and inertia of the process are determined by the inertia of the fan. However, disturbances in the dc bus voltage have a coupling effect on both the speed and the output power.
(4) Energy distribution of storage battery and super capacitor of energy storage system under control of virtual direct current motor
The converter 1 is connected to a lithium battery, the moment of inertia is J-4, and the damping parameter is D-5; the converter 2 is connected with a super capacitor, the moment of inertia of the super capacitor is J-0.5, and the damping parameter is D-20. The converter 2 has a faster response speed.
In the disturbance process, the larger the parameter D of the converter is, the smaller the steady-state power born by the converter is; but the smaller J, the faster response speed and the better short-time power sharing capability are achieved.
(5) DC load interface under control of virtual DC motor
As shown in fig. 15, the dynamics of the output terminal voltage of the load converter.
The virtual direct current motor can well maintain the voltage of the load end as a rated value, meanwhile, in order to respond to the disturbance of the voltage of the direct current bus and improve the stability of the voltage of the direct current bus, under the condition that the voltage of the direct current bus is low after being disturbed, the voltage value of the load is actively reduced, less power is taken from the bus, and the recovery of the voltage of the bus is effectively supported.
(6) Of ac load interfaces under control of virtual synchronous machines
The ac load converter employs a virtual synchronous motor control strategy whose dynamic response is shown in fig. 16.
The virtual synchronous generator control can well ensure the power supply to the local alternating current load and meet the requirements of load voltage and frequency. The dynamic coupling between the output power of the ac load and the dc bus voltage is weak, and the dc side disturbance has little effect on the ac load.
It should be noted that the summary and the detailed description of the invention are intended to demonstrate the practical application of the technical solutions provided by the present invention, and should not be construed as limiting the scope of the present invention. Various modifications, equivalent alterations, and improvements will occur to those skilled in the art and are intended to be within the spirit and scope of the invention. Such changes and modifications are intended to be included within the scope of the appended claims.
Claims (8)
1. A power distribution method of an intelligent building direct current power distribution system comprises a power distribution converter, a direct current bus, distributed energy sources, an energy storage unit, a load and interface converter; the distribution converter is connected to a direct current bus after converting alternating current into direct current; the distributed power supply, the energy storage unit and the load are connected to the direct current bus through the interface converter; the method is characterized in that: the method comprises the following steps:
1) the interface converter is integrated with virtual motor control;
2) the interface converter is controlled autonomously;
the interface converter includes: an AC/DC converter, a DC/DC converter, and a DC/AC inverter, the virtual machine control comprising: virtual synchronous motor control and virtual direct current motor control.
2. The power distribution method of the intelligent building direct current power distribution system according to claim 1, characterized in that: the AC/DC converter and the DC/AC inverter are controlled by a virtual synchronous motor in a fusion way, and the DC/DC converter is controlled by a virtual direct current motor.
3. The power distribution method of the intelligent building direct current power distribution system according to claim 2, characterized in that: the virtual synchronous motor control includes:
1) determining a mechanical equation for the virtual synchronous machine represented by:
<mrow> <mi>J</mi> <mfrac> <mrow> <mi>d</mi> <mi>&omega;</mi> </mrow> <mrow> <mi>d</mi> <mi>t</mi> </mrow> </mfrac> <mo>=</mo> <msub> <mi>T</mi> <mi>m</mi> </msub> <mo>-</mo> <msub> <mi>T</mi> <mi>e</mi> </msub> <mo>-</mo> <msub> <mi>T</mi> <mi>d</mi> </msub> <mo>=</mo> <msub> <mi>T</mi> <mi>m</mi> </msub> <mo>-</mo> <msub> <mi>T</mi> <mi>e</mi> </msub> <mo>-</mo> <mi>D</mi> <mrow> <mo>(</mo> <mi>&omega;</mi> <mo>-</mo> <msub> <mi>&omega;</mi> <mn>0</mn> </msub> <mo>)</mo> </mrow> <mo>,</mo> </mrow>
wherein J is the rotational inertia of the virtual motor and has the unit of kg.m2(ii) a When the number of pole pairs is 1, the mechanical angular velocity ω of the virtual synchronous motor is the electrical angular velocity, ω being0The unit is rad/s for the synchronous angular speed of the power grid; t ism、TeAnd TdAre respectively virtualThe mechanical torque, the electromagnetic torque and the damping torque of the synchronous motor are in the unit of N.m; d is a damping coefficient with the unit of N.m.s/rad;
the electromagnetic torque TeAs shown in the following formula:
Te＝Pe/ω＝(eaia+ebib+ecic)/ω，
wherein e isabcTo virtual motor potential, iabcFor outputting current, P, to a virtual motoreElectromagnetic power output for the virtual motor;
2) determining an electromagnetic equation of the virtual synchronous machine as shown in the following formula:
<mrow> <mi>L</mi> <mfrac> <mrow> <msub> <mi>di</mi> <mrow> <mi>a</mi> <mi>b</mi> <mi>c</mi> </mrow> </msub> </mrow> <mrow> <mi>d</mi> <mi>t</mi> </mrow> </mfrac> <mo>=</mo> <msub> <mi>e</mi> <mrow> <mi>a</mi> <mi>b</mi> <mi>c</mi> </mrow> </msub> <mo>-</mo> <msub> <mi>u</mi> <mrow> <mi>a</mi> <mi>b</mi> <mi>c</mi> </mrow> </msub> <mo>-</mo> <msub> <mi>Ri</mi> <mrow> <mi>b</mi> <mi>c</mi> </mrow> </msub> <mo>,</mo> </mrow>
wherein L is the synchronous inductance of the virtual synchronous motor, R is the synchronous resistance of the virtual synchronous motor, uabcIs the terminal voltage of the virtual synchronous motor;
3) adjusting an active instruction of the virtual synchronous motor:
adjusting mechanical torque T of a virtual synchronous machinemTo realize the regulation of the active command of the virtual synchronous machine, said mechanical torque TmComprising a mechanical torque command T0And a frequency deviation feedback command Δ T;
the mechanical torque command T0As shown in the following formula:
T0＝Pref/ω，
wherein, PrefAn active instruction of the virtual synchronous motor;
the frequency deviation feedback command Δ T is expressed as follows:
ΔT＝-kf(f-f0)，
wherein f is the frequency of the terminal voltage of the virtual synchronous motor, f0For the grid reference frequency, kfIs a frequency modulation coefficient;
4) adjusting the terminal voltage and the reactive power of the virtual synchronous motor:
adjusting the virtual electric potential E of the virtual synchronous motor to adjust the terminal voltage and the reactive power of the virtual synchronous motor;
the virtual potential E is represented by the following equation:
E＝E0+ΔEQ+ΔEU，
wherein E is0Is the no-load potential of the virtual synchronous motor, the terminal voltage when the no-load is running off the network; delta EQIs the potential of the reactive power part; delta EUIs the output potential of the terminal voltage regulating unit;
potential deltae of the reactive power sectionQAs shown in the following formula:
ΔEQ＝kq(Qref-Q)，
wherein k isqTo adjust the coefficient of reactive power, QrefFor the reactive instruction, the instantaneous reactive power Q output by the terminal is as follows:
output potential delta E of terminal voltage regulation unitUAs shown in the following formula:
ΔEU＝kv(Uref-U)，
wherein k isvFor regulating the coefficient of voltage, UrefAnd U is the instruction value and the true value of the effective value of the terminal voltage respectively;
the virtual synchronous motor virtual potential E voltage vector is shown as follows:
wherein,is the phase of the virtual synchronous machine.
4. The power distribution method of the intelligent building direct current power distribution system according to claim 2, characterized in that: the virtual direct current motor control comprises:
1) determining a mechanical equation of the virtual DC motor represented by:
<mrow> <mi>J</mi> <mfrac> <mrow> <mi>d</mi> <mi>&omega;</mi> </mrow> <mrow> <mi>d</mi> <mi>t</mi> </mrow> </mfrac> <mo>=</mo> <msub> <mi>T</mi> <mi>m</mi> </msub> <mo>-</mo> <msub> <mi>T</mi> <mi>e</mi> </msub> <mo>-</mo> <mi>D</mi> <mrow> <mo>(</mo> <mi>&omega;</mi> <mo>-</mo> <msub> <mi>&omega;</mi> <mn>0</mn> </msub> <mo>)</mo> </mrow> <mo>,</mo> </mrow>
Tm＝Pe/ω＝EI/ω，
wherein: j is the rotational inertia of the virtual motor; d is a damping coefficient; t ism、TeRespectively the mechanical torque and the electromagnetic torque of the virtual motor; omega is mechanical angular velocity; omega0Synchronizing the angular speed for the grid; peElectromagnetic power output for the virtual motor; e is a virtual potential, and I is a virtual current;
2) determining an electrical equation of the virtual DC motor as shown in the following formula:
E＝CTφω，
E＝U+IRa，
e is a virtual potential; i is a virtual current; cTIs a torque coefficient; u is terminal voltage; raIs the equivalent resistance of the armature; phi is the magnetic flux and omega is the mechanical angular velocity.
5. The power distribution method of the intelligent building direct current power distribution system according to claim 1, characterized in that: the interface converter autonomous control comprises: and the load electricity utilization information acquired by the interface converter is subjected to feedback regulation control.
6. The power distribution method of the intelligent building direct current power distribution system according to claim 1, characterized in that: the distributed energy source comprises: wind power generators and photovoltaic panels.
7. The power distribution method of the intelligent building direct current power distribution system according to claim 1, characterized in that: the energy storage unit includes: super capacitor and battery.
8. The power distribution method of the intelligent building direct current power distribution system according to claim 1, characterized in that: the load includes: dc loads and ac loads.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201610512903.7A CN107565541A (en) | 2016-06-30 | 2016-06-30 | A kind of distribution method of intelligent building direct-flow distribution system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201610512903.7A CN107565541A (en) | 2016-06-30 | 2016-06-30 | A kind of distribution method of intelligent building direct-flow distribution system |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN107565541A true CN107565541A (en) | 2018-01-09 |
Family
ID=60969962
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201610512903.7A Pending CN107565541A (en) | 2016-06-30 | 2016-06-30 | A kind of distribution method of intelligent building direct-flow distribution system |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN107565541A (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108767840A (en) * | 2018-07-26 | 2018-11-06 | 深圳供电局有限公司 | Power supply and utilization equipment behavior management system and method |
| CN110212515A (en) * | 2019-04-30 | 2019-09-06 | 华北电力大学（保定） | The adaptive virtual DC motor control method of DC grid DAB type inverter |
| CN110957714A (en) * | 2019-11-07 | 2020-04-03 | 中国电建集团江西省电力设计院有限公司 | Virtual direct current motor control method for stabilizing voltage fluctuation of direct current microgrid of charging station |
| CN111030075A (en) * | 2019-11-26 | 2020-04-17 | 深圳供电局有限公司 | DC power supply and distribution system control method |
| CN111856311A (en) * | 2020-07-06 | 2020-10-30 | 上海交通大学 | Distributed power island detection method and system for medium and low voltage DC systems |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103972928A (en) * | 2014-04-18 | 2014-08-06 | 国家电网公司 | Microgrid and microsource control method based on virtual synchronous electric generator |
| CN104201665A (en) * | 2014-08-29 | 2014-12-10 | 国家电网公司 | Virtual direct current generator-based direct current converter control method for load |
| CN104578166A (en) * | 2015-01-29 | 2015-04-29 | 国家电网公司 | Alternating current-direct current micro-grid system on basis of electricity energy collector |
| CN104716886A (en) * | 2015-03-31 | 2015-06-17 | 西安交通大学 | Virtual impedance voltage converter-based control method of virtual synchronous motor |
| CN104953686A (en) * | 2014-03-24 | 2015-09-30 | 国家电网公司 | Control method for charge-discharge virtual synchronization motor for electromobile energy storage |
-
2016
- 2016-06-30 CN CN201610512903.7A patent/CN107565541A/en active Pending
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104953686A (en) * | 2014-03-24 | 2015-09-30 | 国家电网公司 | Control method for charge-discharge virtual synchronization motor for electromobile energy storage |
| CN103972928A (en) * | 2014-04-18 | 2014-08-06 | 国家电网公司 | Microgrid and microsource control method based on virtual synchronous electric generator |
| CN104201665A (en) * | 2014-08-29 | 2014-12-10 | 国家电网公司 | Virtual direct current generator-based direct current converter control method for load |
| CN104578166A (en) * | 2015-01-29 | 2015-04-29 | 国家电网公司 | Alternating current-direct current micro-grid system on basis of electricity energy collector |
| CN104716886A (en) * | 2015-03-31 | 2015-06-17 | 西安交通大学 | Virtual impedance voltage converter-based control method of virtual synchronous motor |
Non-Patent Citations (1)
| Title |
|---|
| 盛万兴等: "一种基于虚拟电机控制的能量路由器", 《中国电机工程学报》 * |
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108767840A (en) * | 2018-07-26 | 2018-11-06 | 深圳供电局有限公司 | Power supply and utilization equipment behavior management system and method |
| CN110212515A (en) * | 2019-04-30 | 2019-09-06 | 华北电力大学（保定） | The adaptive virtual DC motor control method of DC grid DAB type inverter |
| CN110212515B (en) * | 2019-04-30 | 2023-09-26 | 华北电力大学（保定） | Adaptive virtual DC motor control method for DAB type converter in DC grid |
| CN110957714A (en) * | 2019-11-07 | 2020-04-03 | 中国电建集团江西省电力设计院有限公司 | Virtual direct current motor control method for stabilizing voltage fluctuation of direct current microgrid of charging station |
| CN110957714B (en) * | 2019-11-07 | 2021-04-23 | 中国电建集团江西省电力设计院有限公司 | A virtual DC motor control method to suppress the voltage fluctuation of the charging station DC microgrid |
| CN111030075A (en) * | 2019-11-26 | 2020-04-17 | 深圳供电局有限公司 | DC power supply and distribution system control method |
| CN111856311A (en) * | 2020-07-06 | 2020-10-30 | 上海交通大学 | Distributed power island detection method and system for medium and low voltage DC systems |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Zhong | Virtual synchronous machines: A unified interface for grid integration | |
| Singh et al. | Power electronics in hydro electric energy systems–A review | |
| CN104953686B (en) | Control method for charge-discharge virtual synchronization motor for electromobile energy storage | |
| CN114172176B (en) | Flywheel energy storage array control method and system applied to wind turbine generator set | |
| CN106887847B (en) | A microgrid with variable frequency transformer direct load control and its operation method | |
| JP2003339118A (en) | Distributed power supply system | |
| CN110797891B (en) | Flywheel energy storage system of double three-phase brushless direct current motor and control method thereof | |
| CN102709945B (en) | Energy-storage wind power generation system with squirrel-cage generator | |
| CN106786787B (en) | A large-capacity energy storage power station connected to the grid via a synchronous motor | |
| CN107565541A (en) | A kind of distribution method of intelligent building direct-flow distribution system | |
| Chatterjee et al. | An improved current balancing technique of two-winding IG suitable for wind-PV-based grid-isolated hybrid generation system | |
| Ahmadi et al. | Voltage and frequency control in smart distribution systems in presence of DER using flywheel energy storage system | |
| CN114844093A (en) | Photovoltaic grid-connected system and control method thereof | |
| CN102437807B (en) | Variable frequency transformer control system | |
| CN117293855B (en) | Novel energy station with adjustable inertia and grid connection method | |
| Ellabban et al. | A new closed loop speed control of induction motor fed by a high performance Z-source inverter | |
| Monroy‐Morales et al. | Frequency control in an isolated wind‐diesel hybrid system with energy storage and an irrigation water supply system | |
| Goel et al. | Modeling and control of isolated hybrid system using wind driven DFIG and hydro driven SCIG | |
| CN108599250A (en) | A kind of frequency optimization method based on virtual synchronous generator control | |
| CN206807012U (en) | A kind of micro-capacitance sensor of variable frequency transformer direct load control | |
| Ryvkin et al. | Approaches to control design for micro hydropower plant with induction generator | |
| Arutchelvi et al. | Grid connected hybrid dispersed power generators based on PV array and wind-driven induction generator | |
| Kim et al. | Novel structure of single-phase generator from three-phase induction machine: Modeling and simulation | |
| Wang et al. | Characteristics research of wind power generator interfaced to grid via solid state transformer with energy storage device | |
| Kumar et al. | Novel control for voltage boosted matrix converter based wind energy conversion system with practicality |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| RJ01 | Rejection of invention patent application after publication |
Application publication date: 20180109 |
|
| RJ01 | Rejection of invention patent application after publication |