CN104078982B - A kind of micro-grid connection based on spatial load forecasting is to from network operation mode switching method - Google Patents

Abstract

The invention discloses a kind of micro-grid operation mode based on spatial load forecasting and be transformed into control method from network operation by being incorporated into the power networks, in micro-capacitance sensor, each control appliance utilizes EPON fiber plant rapid communication, based on GOOSE mechanism the whole network modeling of 61850, realize the switching value information of micro-capacitance sensor the whole network, analog quantity information, the quick exchange of tripping operation information, transfer to from network operation mode process at micro-capacitance sensor from the pattern of being incorporated into the power networks, according to micro-capacitance sensor generate output, the stability margin of load condition and energy-storage system, cut-out generating equipment or load, ensure that micro-capacitance sensor can from net stable operation.The method carries out GOOSE modeling to the switching value of micro-capacitance sensor and performance number P analog quantity etc., by spatial load forecasting, dynamically solves micro-capacitance sensor and transfers to from load capacity during network operation.

Description

A kind of micro-grid connection based on spatial load forecasting is to from network operation mode switching method

Technical field

The invention discloses a kind of micro-capacitance sensor to be switched from a kind of mentality of designing of network operation pattern by the pattern that is incorporated into the power networks, relate to distribution field, relay protection field and communication field.

Background technology

By the increase in demand of global energy and the impact of environmental pollution, various countries carry forward vigorously development wind power generation, solar power generation and other clean electric power generation technology in the world, China also helps generation of electricity by new energy in policy, plan according to " 12 ", government is subsidized distributed power generation rate for incorporation into the power network, distributed power source supplementing as bulk power grid, accesses power distribution network on the spot, and current distributed photovoltaic power generation online policy is decontroled.Distributed power generation belongs to intermittent energy source, has unsteadiness, can cause fluctuation and the flickering of system voltage, and distributed power generation and energy-storage system are formed micro-capacitance sensor, can effectively stabilize the fluctuation of voltage.

The operational mode of micro-capacitance sensor is divided into the mode of being incorporated into the power networks and from network operation mode, generally micro-capacitance sensor and power distribution network are incorporated into the power networks, and when superior system exception or Distribution Network Failure, micro-capacitance sensor band portion important load is from network operation in V/F pattern.When micro-capacitance sensor is in the process of network operation pattern by the patten transformation that is incorporated into the power networks, generating is inconsistent with load capacity in microgrid, carries out stability contorting, play a part variable load plant by energy-storage system to micro-capacitance sensor.As energy storage system capacity is enough large, micro-capacitance sensor Absorbable organic halogens runs, but the cost of investment of energy-storage system is very high, and energy-storage battery exists life problems, and the stable solution cost performance of this micro-capacitance sensor is not high.If micro-capacitance sensor transfers in off-grid process by grid-connected, part generate electricity in micro-capacitance sensor or unessential load are cut away, make the unbalance control of generating and load in microgrid in the stability contorting nargin of energy-storage system, can realize and seamlessly transitting from net switching, ensure important load reliable power supply in micro-capacitance sensor, greatly can reduce the investment of energy-storage system.The active of micro-capacitance sensor allows switching load or generating in the longer time from net; be switched to micro-capacitance sensor again from network operation mode; after Distribution Network Failure or superior system dead electricity; for the energy storage inverter possessing low voltage ride-through function; the low voltage crossing time, 0 voltage ride-through time was generally no more than 150ms, therefore at 625ms; require switching load or generating and the time be switched to from net stable operation is generally no more than 150ms, otherwise energy storage inverter is shut down.

In recent years, computer technology, mechanics of communication, optical fiber technology are fast-developing, and EPON technology uses in a large number in distribution automation.If the GOOSE rapid communication of IEC61850 mechanism is carried out effective integration with EPON, effectively can reduce investment, dynamic load balancing in micro-capacitance sensor can be realized and control, ensure that micro-capacitance sensor is from net stable operation.

Summary of the invention

Object:

Technical problem to be solved by this invention is the defect overcoming prior art, there is provided a kind of micro-grid connection based on spatial load forecasting to from network operation mode switching method, provide a kind of micro-capacitance sensor by a kind of new mentality of designing of pattern switching from network operation pattern that be incorporated into the power networks, can realize and taking over seamlessly of switching from net, ensure important load reliable power supply in micro-capacitance sensor.

Technical scheme:

Main technical content of the present invention is as follows: rely on the EPON optical-fibre communications of power distribution network as communication system, utilize the GOOSE communication mechanism of ICE61850 to carry out the snap informations such as switching value, analog quantity, tripping operation information to exchange, transfer to from the process of network operation at micro-capacitance sensor by being incorporated into the power networks, dynamic calculation and cut-out generating or load, form the balance of generating and load in micro-capacitance sensor, ensure that micro-capacitance sensor is from net safe and stable operation, comprises four steps:

1, the GOOSE mechanism communication network based on ICE61850 is formed by switch and EPON between each protection supervisory equipment and micro-capacitance sensor mode control device in micro-capacitance sensor.

2, micro-capacitance sensor the whole network carries out the whole network modeling based on the GOOSE mechanism of ICE61850; it is made to support on the basis that the information such as switching value, trip signal transmits; also support GOOSE transmission or analog signal, in micro-capacitance sensor, the analog quantity such as the running status switching value of each protection supervisory equipment and active power gives micro-capacitance sensor mode control device on the net by GOOSE.

3, micro-capacitance sensor internal loading or generating are according to characteristic and importance, carry out excision priority level initializing by configuration file.

4, the inspection isolated island sent from net order or grid-connected point interface device that micro-capacitance sensor mode control device receives that higher level supervisory control system issues starts after net order, first can calculate micro-capacitance sensor current power vacancy, and cut-out generating or load, ensure the relative equilibrium of power between generating and load in micro-capacitance sensor, disconnect again and site switch, control energy storage inverter and switched to from network operation mode by the mode of being incorporated into the power networks.

Load or generating equipment excision order are first configured by configuration file;

Cutting load is divided into the many wheels of many groups, wherein first group is sorted according to branch, second group is sorted according to segmentation, 3rd group is sorted according to circuit, excision order be followed successively by first group of first round, first group second take turns, the like, second group of first round, second group second take turns, the like, the 3rd group of first round, the 3rd group second take turns, the like;

Cut generating equipment to take turns according to one group, the order of excision is GOOSE trip signal more.

In step (4), the inspection isolated island from net order or grid-connected point interface device receiving higher level's supervisory control system when mode transition controller starts after net order, first the power shortage that micro-capacitance sensor runs is calculated, when power shortage is less than the stability margin of energy storage inverter PCS, assign from the preset control command of net directly to energy storage inverter PCS, disconnect and site switch, transfer V/F mode of operation to through time delay after energy storage inverter PCS receives this order, micro-capacitance sensor is from network operation; When power shortage be greater than energy storage inverter PCS from net stability margin time, according to excision order excision generating equipment or load, micro-capacitance sensor is made to meet the condition of stable operation, assign from the preset control command of net to energy storage inverter PCS again, disconnect and site switch, transfer V/F mode of operation to through time delay after energy storage inverter PCS receives this order, micro-capacitance sensor is from network operation.

When $|\stackrel{\·}{P}\mathrm{pcs}+\stackrel{\·}{P}\mathrm{pcc}|\≥\mathrm{KPpcszd}$ Time,

Perform according to excision order $|\stackrel{\·}{P}\mathrm{pcs}+\stackrel{\·}{P}\mathrm{pcc}|-\left|\stackrel{\·}{P}\mathrm{li}\right|$ Or $|\stackrel{\·}{P}\mathrm{pcs}+\stackrel{\·}{P}\mathrm{pcc}|-\left|\stackrel{\·}{P}\mathrm{pi}\right|,$ And record needs the load of excision or the switch sequence number of generating equipment, until then give each power control or load control unit by GOOSE communication by trip signal multicast, power control or load control unit, according to the GOOSE order excision respective switch of concluding a bargin, make micro-capacitance sensor meet the condition of stable operation;

Wherein be respectively energy storage inverter PCS, grid-connected point interface device on send power, for each load control unit send power, for each power control send power, for energy storage inverter PCS from network operation stability margin.

When $|\stackrel{\·}{P}\mathrm{pcs}+\stackrel{\·}{P}\mathrm{pcc}|\≥\mathrm{KPpcszd}$ Time, and $\stackrel{\·}{P}\mathrm{pcs}+\stackrel{\·}{P}\mathrm{pcc}>0$ Time, excision generating equipment.

When $|\stackrel{\&CenterDot;}{P}\mathrm{pcs}+\stackrel{\&CenterDot;}{P}\mathrm{pcc}|\&GreaterEqual;\mathrm{KPpcszd}$ Time, and $\stackrel{\&CenterDot;}{P}\mathrm{pcs}+\stackrel{\&CenterDot;}{P}\mathrm{pcc}<0$ Time, excision load.

The beneficial effect that the present invention reaches:

1, by EPON (EthernetPassiveOpticalNetwork, Ethernet passive optical network) light splitting composition optical-fibre communications net, the GOOSE rapid communication mechanism of IEC61850 is applied to EPON system, realizes micro-capacitance sensor the whole network snap information and exchange, optical fiber can be reduced and repeat to lay.The method carries out GOOSE modeling to the switching value of micro-capacitance sensor and performance number P analog quantity etc., by spatial load forecasting, dynamically solves micro-capacitance sensor and transfers to from load capacity during network operation.

2, dynamic load balancing calculating is carried out according to the performance number of the whole network, quick cut-out load or generator unit in network operation process is transferred to by being incorporated into the power networks at micro-capacitance sensor, the utilance of effective raising distributed power source, realizes micro-capacitance sensor and transfers taking over seamlessly from network operation to by grid-connected.

3, can ensure when system dead electricity from network operation, the reliable power supply of important load can be ensured in microgrid.

Accompanying drawing explanation

Fig. 1 is GOOSE Communication Model schematic diagram;

Fig. 2 is pattern switch control logic block diagram;

Fig. 3 is example micro-capacitance sensor rack schematic diagram;

Fig. 4 is example micro-capacitance sensor GOOSE communication network schematic diagram.

Embodiment

For further setting forth technological means of the present invention, below in conjunction with accompanying drawing and example, specific embodiments of the present invention is described in detail.

Rely on the EPON communication system of power distribution network, in micro-capacitance sensor, set up the rapid communication net of the GOOSE mechanism based on IEC61850 between each control device, model is as Fig. 1.

Micro-capacitance sensor carries out communication modeling based on the GOOSE mechanism of IEC61850, and the apparatus GOOSE models such as mode transition controller, grid-connected point interface device, power control, energy storage inverter PCS are as following table:

Load or generating excision order need first to be configured by configuration file, cutting load is divided into the many wheels of many groups, wherein first group is sorted according to branch, second group is sorted according to segmentation, 3rd group is sorted according to circuit, excision order be followed successively by first group of first round, first group second take turns ... second group of first round, second group second take turns ... 3rd group of first round, the 3rd group second take turns ... cutting generating generally to take turns according to one group more, the order of excision is GOOSE trip signal, need carry out modeling in Communication Model.

The GOOSE analog quantity of each rating of set value P in mode transition controller real-time reception micro-capacitance sensor, circuit is pointed to for positive direction with micro-capacitance sensor bus in the direction of P.The inspection isolated island from net order or grid-connected point interface device receiving higher level's supervisory control system when mode transition controller starts after net order, first the power shortage that micro-capacitance sensor runs is calculated, when power shortage is less than the stability margin of energy-storage system PCS, assign from the preset control command of net directly to energy-storage system PCS, disconnect and site switch, transfer V/F mode of operation to through short time delay after PCS receives this order, micro-capacitance sensor is from network operation.When power shortage be greater than energy storage inverter PCS from net stability margin time, namely when

$|\stackrel{\&CenterDot;}{P}\mathrm{pcs}+\stackrel{\&CenterDot;}{P}\mathrm{pcc}|\&GreaterEqual;\mathrm{KPpcszd}$ Time,

Perform according to excision order $|\stackrel{\&CenterDot;}{P}\mathrm{pcs}+\stackrel{\&CenterDot;}{P}\mathrm{pcc}|-\left|\stackrel{\&CenterDot;}{P}\mathrm{li}\right|$ Or $|\stackrel{\&CenterDot;}{P}\mathrm{pcs}+\stackrel{\&CenterDot;}{P}\mathrm{pcc}|-\left|\stackrel{\&CenterDot;}{P}\mathrm{pi}\right|$ , and record needs the switch sequence number of excision, until then each device is given by GOOSE communication by trip signal multicast, each device is according to the GOOSE order excision respective switch of concluding a bargin, micro-capacitance sensor is made to meet the condition of stable operation, assign from the preset control command of net to energy-storage system PCS again, disconnect and site switch, transfer V/F mode of operation to through short time delay after PCS receives this order, micro-capacitance sensor is from network operation, and logic flow is shown in Fig. 2.

Wherein be respectively energy storage inverter PCS, grid-connected point interface device on send power, for each load control unit send power, for each power control send power, for energy storage inverter PCS from network operation stability margin.

Example explanation

As in the micro-capacitance sensor model of Fig. 3 example, the power direction of each control appliance of micro-capacitance sensor points to circuit by bus, Kp1, Kp2, Kp3, Kp4 is respectively power supply connecting valve, each power supply generate output is 400KW, all install power control unit, Kpcc is and site switch, install grid-connected point interface device, Kpcs connects energy storage inverter PCS, be 300KW from net stability margin, Kl01, Kl02, Kl03, Kl04 is four outlet switchs, installing load control unit, Kf1, Kf2, Kf3 is the block switch on load outlet Kl04, installing load control unit, Kl11, Kl12, Kl21, Kl22, Kl31, Kl32, Kl41, Kl42 is the branch switch on load outlet Kl04, each branch load capacity 150KVA, separately having can not cutting load 1, 2 capacity.

GOOSE communication network carries out networking by switch and EPON, and model is that Fig. 4, GOOSE communication modeling is as follows:

If load significance level is respectively from high to low: Kl12, Kl31, Kl2l, Kl41, Kl42, Kl11, Kl32, Kl22, the significance level of circuit is respectively from high to low: circuit Kl01, Kl02, Kl03, Kl04, arranges cutting load order to be by configuration file:

The first group of first round: Kl22

Take turns for first group second: Kl32

First group of third round: Kl11

First group of fourth round: Kl42

Take turns for first group the 5th: Kl41

Take turns for first group the 6th: Kl2l

Take turns for first group the 7th: Kl31

Take turns for first group the 8th: Kl12

The second group of first round: Kf3

Take turns for second group second: Kf2

Second group of third round: Kf1

The 3rd group of first round: Kl04

Take turns for 3rd group second: Kl03

3rd group of third round: Kl02

3rd group of fourth round: Kl01

Suppose power supply put into operation order be Kp01, Kp02, Kp03, Kp04 respectively, then power supply excision order be respectively:

The first group of first round: Kp04

Take turns for first group second: Kp03

First group of third round: Kp02

First group of fourth round: Kp01

For simplified illustration, suppose that Kl01, Kl02, Kl03 all disconnect, only illustrate with Kl04 circuit, micro-capacitance sensor when being incorporated into the power networks, mode transition controller receive from net order or and mesh point device the order of inspection isolated island after, there is following operating condition:

1, generating is greater than load, and power difference exceedes the stability margin of energy storage inverter:

Suppose all full power generatings of 4 power supplys, generated output is-400KW, can not cutting load 1, 2 current loads are 100KVA, each branch current loads is 50KVA, current power difference Ppcc+Ppcs=-(-4*400+2*100+8*50)=1000K, exceed energy storage inverter from net stability margin 300K, and be greater than 0, generating need be excised, according to excision order, calculate as excision Kp04, after Kp03, power difference is Ppcc+Ppcs=-(-2*400+2*100+8*50)=200K, be less than energy storage inverter from net stability margin, mode transition controller generates Kp04, the GOOSE trip signal of Kp03, and control micro-capacitance sensor and transfer to from network operation mode.

2, the power difference of generating and load is within the scope of the stability margin of inverter:

Suppose 2 power supply full power generatings, generated output is-400KW, 2 power supplys are stopped transport, 100KVA can not be by cutting load 1,2 current loads, each branch current loads is 50KVA, current power difference Ppcc+Ppcs=-(-2*400+2*100+8*50)=200K, is less than energy storage inverter from net stability margin 300K, mode transition controller does not generate GOOSE trip signal, only controls micro-capacitance sensor and transfers to from network operation mode.

3, generating is less than load, and power difference exceedes the stability margin of energy storage inverter, and cut-out branched line can meet the stability requirement of micro-capacitance sensor:

Suppose 2 power supply full power generatings, generated output is-400KW, 2 power supplys are stopped transport, can not cutting load 1, 2 current loads are 400KVA, each branch current loads is 90KVA, current power difference Ppcc+Ppcs=-(-2*400+2*400+8*90)=-720K, exceed energy storage inverter from net stability margin 300K, and be less than 0, load need be excised, according to excision order, calculate as excision branch Kl22, Kl32, Kl11, Kl42, after Kl41, power difference is Ppcc+Ppcs=-(-2*400+2*400+3*90)=270K, be less than energy storage inverter from net stability margin 300K, mode transition controller generates Kl22, Kl32, Kl11, Kl42, the GOOSE trip signal of Kl41, and control micro-capacitance sensor and transfer to from network operation mode.

4, generating is less than load, and power difference exceedes the stability margin of energy storage inverter, excises the stability requirement that whole branched line can't meet micro-capacitance sensor

Suppose 1 power supply generating, generated output is-300KW, 3 power supplys are stopped transport, can not cutting load 1, 2 current loads are 320KVA, each branch current loads is 50KVA, current power difference Ppcc+Ppcs=-(-300+2*320+8*50)=-740K, exceed energy storage inverter from net stability margin 300K, and be less than 0, load need be excised, according to excision order, calculate when first group eight is taken turns after load all cuts away, power difference is Ppcc+Ppcs=-(-300+2*320)=-340K, still energy storage inverter is exceeded from net stability margin, then cancel first group of excision order, change and excised by second group of excision order, according to excision order, calculate as excision Kf3, after Kf2, power difference is Ppcc+Ppcs=-(-300+320+4*50)=-220K, be less than energy storage inverter from net stability margin, mode transition controller generates Kf3, the GOOSE trip signal of Kf2, and control micro-capacitance sensor and transfer to from network operation mode.

Claims (5)

1. one kind based on the micro-grid connection of spatial load forecasting to from network operation mode switching method, it is characterized in that: in micro-capacitance sensor, each control appliance utilizes EPON fiber plant rapid communication, based on GOOSE mechanism the whole network modeling of ICE61850, realize the switching value information of micro-capacitance sensor the whole network, analog quantity information, the quick exchange of tripping operation information, transfer to from network operation mode process at micro-capacitance sensor from the pattern of being incorporated into the power networks, according to micro-capacitance sensor generate output, the stability margin of load condition and energy-storage system, cut-out generating equipment or load, ensure that micro-capacitance sensor can from net stable operation, specifically comprise the following steps:

(1) the GOOSE mechanism communication network based on ICE61850 is formed by switch and EPON between each protection supervisory equipment and micro-capacitance sensor mode transition controller in micro-capacitance sensor;

(2) micro-capacitance sensor the whole network carries out the whole network modeling based on the GOOSE mechanism of ICE61850, it is made to support on the basis that switching value, trip signal information transmit, also support GOOSE transmission or analog signal, in micro-capacitance sensor, the running status switching value of each protection supervisory equipment and active power analog quantity give micro-capacitance sensor mode transition controller on the net by GOOSE;

(3) micro-capacitance sensor internal loading or generating equipment are according to characteristic and importance, carry out excision priority level initializing by configuration file;

(4) the inspection isolated island sent from net order or grid-connected point interface device that micro-capacitance sensor mode transition controller receives that higher level supervisory control system issues starts after net order, first calculate micro-capacitance sensor current power vacancy, and cut-out generating equipment or load, ensure the relative equilibrium of power between generating equipment and load in micro-capacitance sensor, disconnect again and site switch, control energy storage inverter and switch to from network operation mode by the mode of being incorporated into the power networks;

Load or generating equipment excision order are first configured by configuration file;

Cutting load is divided into the many wheels of many groups, wherein first group is sorted according to branch, second group is sorted according to segmentation, 3rd group is sorted according to circuit, excision order be followed successively by first group of first round, first group second take turns, the like, second group of first round, second group second take turns, the like, the 3rd group of first round, the 3rd group second take turns, the like;

Cut generating equipment to take turns according to one group, the order of excision is GOOSE trip signal more.

2. the micro-grid connection based on spatial load forecasting according to claim 1 is to from network operation mode switching method, it is characterized in that: in step (4), the inspection isolated island from net order or grid-connected point interface device receiving higher level's supervisory control system when mode transition controller starts after net order, first the power shortage that micro-capacitance sensor runs is calculated, when power shortage is less than the stability margin of energy storage inverter PCS, assign from the preset control command of net directly to energy storage inverter PCS, disconnect and site switch, V/F mode of operation is transferred to through time delay after energy storage inverter PCS receives this order, micro-capacitance sensor is from network operation, when power shortage be greater than energy storage inverter PCS from net stability margin time, according to excision order excision generating equipment or load, micro-capacitance sensor is made to meet the condition of stable operation, assign from the preset control command of net to energy storage inverter PCS again, disconnect and site switch, transfer V/F mode of operation to through time delay after energy storage inverter PCS receives this order, micro-capacitance sensor is from network operation.

3. the micro-grid connection based on spatial load forecasting according to claim 2 is to from network operation mode switching method, it is characterized in that:

When $|\stackrel{\&CenterDot;}{P}pcs+\stackrel{\&CenterDot;}{P}pcc|\&GreaterEqual;KPpcszd$ Time,

Perform according to excision order or and record needs the load of excision or the switch sequence number of generating equipment, until then give each power control or load control unit by GOOSE communication by trip signal multicast, power control or load control unit, according to the GOOSE order excision respective switch of concluding a bargin, make micro-capacitance sensor meet the condition of stable operation;

Wherein be respectively energy storage inverter PCS, grid-connected point interface device on send power, for each load control unit send power, for each power control send power, for energy storage inverter PCS from network operation stability margin.

4. the micro-grid connection based on spatial load forecasting according to claim 3 is to from network operation mode switching method, it is characterized in that: when $|\stackrel{\&CenterDot;}{P}pcs+\stackrel{\&CenterDot;}{P}pcc|\&GreaterEqual;KPpcszd$ Time, and $\stackrel{\&CenterDot;}{P}pcs+\stackrel{\&CenterDot;}{P}pcc>0$ Time, excision generating equipment.

5. the micro-grid connection based on spatial load forecasting according to claim 3 is to from network operation mode switching method, it is characterized in that: when $|\stackrel{\&CenterDot;}{P}pcs+\stackrel{\&CenterDot;}{P}pcc|\&GreaterEqual;KPpcszd$ Time, and $\stackrel{\&CenterDot;}{P}pcs+\stackrel{\&CenterDot;}{P}pcc<0$ Time, excision load.