Intelligent Grid Management of DC Grids in Production

Transcription

1 DC-INDUSTRIE November 2018 Intelligent Grid Management of DC Grids in Production Verbundvorhaben: DC-Industrie Intelligentes offenes DC-Netz in der Industrie für hocheffiziente Systemlösungen mit elektrischen Antrieben

2 Agenda Requirements for an intelligent grid management Tasks of grid management Expansion levels of grid management Control concepts Seite 2 November 2017

3 The motivation for intelligent grid management is diverse Potentials of Ultra-Efficient Power Distribution in Industrial DC grids: Installation Potentials Lower wiring Decentralized device arrangement: up to 95% less wiring Lower errors and service costs Space reduction of control cabinets Increasing the modularization of machines Availability Potentials Higher plant availability Short grid failure: approx. 98% increase in availability Reduction in costs by avoiding damages to the system Peak power reduction Energetic Potentials Lowering conversion losses approx. 10% due to elimination of conversion points Use of regenerative energy (12%) Use immediately: about 90 Save: about 9% Reloading: approx. 1% Heat up: only in emergency cases Technical Equipment Potentials Lower device costs Up to 20% due to the elimination of power electronics Increase efficiency of system components Small dimensioning: approx. 60% potential savings Elimination of redundancies: approx. 30% potential savings Seite 3 November 2017

4 The requirements for grid management can be divided into four areas Requirements for grid management: Operation When supplying several machines via a DC system, a secure supply must be ensured. As little control as possible during operation Energy flexibility: The energy supply must follow production Planning procedure, configuration and reconfiguration Rescheduling / additions need to be as easy and flexible as they are today (with AC) Self-configurable or configurable with as less effort as possible Stations can change step by step in the life cycle of the plant -> no reconfiguration of the energy grid Communication should be as low and effortless as possible Requirements for durability & reliability Energy Management: No power failures due to additional ICT Economic and ecological efficiency Energy savings > 10% (compared to today, no recuperation) Making external energy demand more flexible is an important goal Seite 4 November 2017

5 Agenda Requirements for an intelligent grid management Tasks of grid management Expansion levels of grid management Control concepts Seite 5 November 2017

6 The tasks of grid management go beyond the simple energy supply Tasks that are realized by grid management : Production Planning grid management Resource Management Quality of the Supply Grid Stability Optimized Operational Management Maintenance & Service Supply Reliability Maintaining of the grid operation Monitoring Planning & Projecting Defined Interface Error Handling Consumption Optimization Seite 6 November 2017

7 Agenda Requirements for an intelligent grid management Tasks of grid management Expansion levels of grid management Control concepts Seite 7 November 2017

8 Expanded levels of grid management basic combination decentralized group regulation Extended decentralized group control central grid control irregular Decentralized control via voltage-current control characteristic (characteristic-based control) Decentralized group control + optional adaptation of the voltage-current control characteristic (characteristic-based control) by a grid manager Central control - A grid manager specifies setpoints Communication none none Information exchange Optionally via fieldbus communication (nonreal-time) - voltage band voltage band - Fieldbus communication (real time) Seite 8 November 2017

9 Agenda Requirements for an intelligent grid management Tasks of grid management Expansion levels of grid management Control concepts Seite 9 November 2017

10 grid subscriber in the DC grid Producer Provision of energy Prosumer Optimized management Consumer Value-adding or necessary, not value-adding DC-branch Sensor Power flow control through fault management: Detecting and correcting / isolating occurring fault conditions Return of the grid in safe condition Additional status detection of the DC-BUS Seite 10 November 2017

11 Current Characteristic-based control for decentralized grid management The load balancing takes place in the expansion stage, decentralized as well as extended group control via a characteristic-based control. Every active device implements this regulation. The active device realizes a quasi-stationary current-voltage characteristic at the DC bus connection terminal. The characteristic-based control is set via interpolation points. Terminal voltage All power sources operate as voltage controlled current sources. Seite 11 November 2017

12 Exemplary application of the characteristic based control Feed-in current of PV system and mains supply depending on the load current: Restoring Energy reference PV power plant PV power plant Grid supply re-storage current from PV power plant Grid supply Load Seite 12 November 2017

13 Decentralized grid management in plants closed-loop control line for load flow management control characteristics line for energy management Sub-grid1 Plant 1 PL C Storage DC/DC Converter switch Measuring device DC/AC Inverter Grid feed-in AC source AC/DC Converter Plant n DC source DC/DC Converter PL C switch Measuring device DC/AC Inverter AC grid Storage Switch Measurin g device DC/AC Inverter DC/DC Converter Motor DC source AC source AC load DC load AFE Rectifier Seite 13 November 2017

14 Conclusion and outlook The requirements for grid management were declared. The tasks of grid management have been defined. Four stages of grid management have been defined. Initial studies show that the functionality of the control system, prioritization and thus first economic optimization with characteristic curves are possible. Further investigations with regard to the stability will be carried out. The grid management will be implemented in demonstrators. Seite 14 November 2017

15 Thank you for your attention! Assoz. Partner: ABB STOTZ-KONTAKT, E-T-A Elektrotechnische Apparate, HARTING, HOMAG Group, Jean Müller GmbH Elektrotechnische Fabrik, U.I. Lapp, LEONI Special Cables, Phoenix Contact, SEW-Eurodrive, Yaskawa, ZVEI. Seite 15 November 2017