CONTROL METHOD OF A VIRTUAL GENERATOR

• US 20170235322A1
• Filed: 01/06/2017
• Published: 08/17/2017
• Est. Priority Date: 02/16/2016
• Status: Active Grant

• Current Assignee: Schneider Electric Industries SAS (Schneider Electric SE)
• Original Assignee: Schneider Electric Industries SAS (Schneider Electric SE)
• Inventors: RAHMANI, Mustapha, GUYON-AUBERT, Caroline, HERRIOT, Yann, GUALINO, David, DENTELLA, Alain, LECHAT-SANJUAN, Sylvain, GANDANEGARA, Grace
• Granted Patent: US 10,452,091 B2
• Time in Patent Office: Days
• CPC Class Codes: G05B 2219/2619 Wind turbines
• CPC Class Codes: G05F 1/66 Regulating electric power
• CPC Class Codes: H02J 2300/10 The dispersed energy generation being of fossil origin, e.g. diesel generators
• CPC Class Codes: H02J 2300/20 The dispersed energy generation being of renewable origin
• CPC Class Codes: H02J 2300/24 of photovoltaic origin
• CPC Class Codes: H02J 2300/28 The renewable source being wind energy wind motors F03D
• CPC Class Codes: H02J 2310/10 The network having a local or delimited stationary reach
• CPC Class Codes: H02J 3/1814 wherein al least one reactive element is actively controlled by a bridge converter, e.g. unified power flow controllers [UPFC]
• CPC Class Codes: H02J 3/1821 using shunt compensators H02J3/1807, H02J3/1878 take precedence
• CPC Class Codes: H02J 3/38 Arrangements for parallely feeding a single network by two or more generators, converters or transformers
• CPC Class Codes: H02J 3/381 Dispersed generators
• CPC Class Codes: H02J 5/00 Circuit arrangements for transfer of electric power between ac networks and dc networks H02J3/36 takes precedence
• CPC Class Codes: Y02E 10/56 Power conversion systems, e.g. maximum power point trackers
• CPC Class Codes: Y02E 40/10 Flexible AC transmission systems [FACTS]
• CPC Class Codes: Y02P 80/14 District level solutions, i.e. local energy networks

Abstract

A method for controlling a virtual generator including at least one renewable power source, an accumulation system including a power and/or energy reserve, an inverter and a control law, the virtual generator delivering an active P/reactive Q electrical power of voltage V and of current I to a microgrid, the voltage V and current I having a frequency f, the active P/reactive Q electrical power controlling, via droop control, the frequency f and the RMS voltage V_rms of the voltage V, respectively, the method including control of the virtual generator via the control law for which it carries out an adjustment of the active P/reactive Q power delivered to the microgrid, the adjustment being capable of compensating for a variation in the active/reactive power consumed by the microgrid.

Claims

1. A method for controlling a virtual generator comprising at least one renewable power source, an accumulation system comprising a power and/or energy reserve, an inverter and a control law, the virtual generator delivering to a microgrid an active P/reactive Q electrical power with a voltage V and a current I, said voltage V and current I having a frequency f, said active/reactive electrical power controlling, via droop control, the frequency f and the RMS voltage V_rms of the voltage V, respectively, the method comprising controlling the virtual generator via the control law for which said virtual generator carries out an adjustment of the active/reactive power delivered to the microgrid, said adjustment being capable of compensating for a variation in the active/reactive power consumed by the microgrid, wherein the accumulation system applies a DC voltage V_ref to first terminals of the renewable power source so that the renewable power source delivers a power P_sr, said power P_sr being liable to exhibit power fluctuations, the accumulation system being controlled in order to compensate for said fluctuations.

2. The method according to claim 1, in which the control law is capable of endowing the virtual generator with the possibility to form the grid via the inverter.

3. The method according to claim 1, in which the control law is capable of connecting the virtual generator in parallel with generator sets.

4. The method according to claim 1, in which the DC voltage V_ref applied to the first output terminals is the result of the conversion of a DC voltage V_PS, at the terminals of a storage system, by a DC/DC converter, the storage system and the DC/DC converter being included within the accumulation system.

5. The method according to claim 1, in which the voltage V_ref is determined as a function of a setpoint power P_sr that the renewable power source must be deliver, the voltage being imposed by the accumulation system.

6. The method according to claim 1, in which the voltage V_ref is determined by a voltage sweep, for example in stages, of the first output terminals, and by simultaneously measuring the amperage of the current produced by the renewable power source and said voltage V_ref.

7. The method according to claim 6, in which the voltage sweep produces power variations in the power delivered by the renewable power source, the accumulation system is controlled in order to compensate for said variations during said sweep.

8. The method according to claim 1, comprising a step of measuring a state of charge of the accumulation system.

9. The method according to claim 1, in which the voltage V_ref is adjusted so that, when the state of charge of the accumulation system is above or equal to a predetermined maximum charge threshold SoC_max, the power P_sr is entirely consumed by the microgrid.

10. The method according to claim 1, in which the state of charge of the accumulation system is maintained at a value that is higher than a minimum state of charge SoC_min.

11. The method according to claim 1, in which a power P_acc is delivered by the accumulation system to the microgrid, via the inverter, when said microgrid has to consume extra power P_sur that the renewable power source is unable to provide.

12. A virtual generator capable of delivering an active P/reactive Q electrical power, with a voltage of frequency f and RMS voltage V_rms, to a microgrid comprising:

a renewable power source;

an accumulation system comprising a power and/or energy reserve;

an inverter;

a control law;

the control law being capable of controlling the virtual generator so that the virtual generator delivers an active P/reactive Q electrical power having a voltage V and a current I to the microgrid, said voltage V and current I having a frequency f, said active P/reactive Q electrical power controlling, via droop control, the frequency f and the RMS voltage V_rms of the voltage V, respectively, and that the virtual generator carries out an adjustment of the active/reactive power delivered to the microgrid when a variation in the active/reactive power consumed by the microgrid occurs, said adjustment being capable of compensating for the variation in the active/reactive power consumed, wherein the accumulation system comprises a storage system and a DC/DC converter, the DC/DC converter connecting the output terminals of the storage system to first output terminals of the renewable power source, and the accumulation system is capable of delivering a voltage V_ref to the first output terminals, according to a setpoint imposed by the control law, from a DC voltage V_PS delivered to the output terminals of the storage system.

13. The virtual generator according to claim 12, in which the control law is capable of endowing the virtual generator with the possibility to form the grid via the inverter.

14. The virtual generator according to claim 12, in which the control law is capable of connecting the virtual generator in parallel with generator sets.

15. The virtual generator according to claim 12, in which the control law is capable of determining the voltage V_ref as a function of a setpoint power P_sr that must be delivered by the renewable power source via the accumulation system.

16. The virtual generator according to claim 15, in which the accumulation system is capable of carrying out a voltage sweep of the first output terminals, and of simultaneously measuring the amperage of the current produced by the renewable power source and said voltage.

17. The virtual generator according to claim 12, in which the control law is capable of making the accumulation system compensate for fluctuations in the power delivered by the renewable power source.

18. The virtual generator according to claim 12, in which the renewable power source comprises photovoltaic panels.

19. The virtual generator according to claim 12, in which the renewable power source comprises wind turbines.