Current procedures and practices on grid code compliance verification of renewable power generation

Modeling and Design of the Vector Control for a Three-Phase Single-Stage Grid-Connected PV System with LVRT Capability according to the Spanish Grid Code

“…In addition, with this approach the control subsystem works as if it were connected to the signal conditioners of a real power subsystem but avoiding the power flow and attaining a safe operation, allowing some risky tests so as to be able to validate the proper behavior of the control algorithms. The sample time (T s ) for the DRTS is set to 5.1196 µs, whereas the sample time of the controller (T reg ) is set to 40.957 µs; the latter has a delay of 3 2 T reg = 61.44 µs in the worst case. Finally, several measurements are displayed and recorded in the host PC in order to monitor the behavior of the grid-connected PV system.…”

“…The increase of the penetration of renewable agents in the energy mix [1], together with the necessity to maintain the stability of the electric power systems make the new grid codes more restrictive nowadays for grid-connected photovoltaic (PV) systems and other renewable agents [2][3][4][5]. For example, these systems must remain connected under certain conditions so as to improve the voltage profile of the utility grid when there are voltage sags [6][7][8].…”

Review of Voltage and Frequency Grid Code Specifications for Electrical Energy Storage Applications

“…There are some requirements in GB Grid Code specific to the frequency control device, such as: (1) if a generating unit supplies customers in an isolation condition, its frequency control device must be able to control system frequency below 52 Hz; (2) the frequency control device (or speed governor) must be capable of operating with an overall speed droop of between 3% and 5%; and (3) the unit load controller or an equivalent device should be able to modify the target frequency either continuously or in a maximum of 0.05 Hz steps over at least the range 50 ± 0.1 Hz (for details, refer to [1,10]). GB Grid Code specifies that generating units need withstand voltage dips down to a certain percentage of the rated voltage (even 0% in some cases) with a specified duration, which is entitled Fault Ride-Through (FRT) or Low Voltage Ride-Through (LVRT) [1,7,10]. The characteristic of FRT/LVRT can be described by a voltage against duration profile, showing the minimum required immunity of generating units to dips of the network system voltage.…”

“…The characteristic of FRT/LVRT can be described by a voltage against duration profile, showing the minimum required immunity of generating units to dips of the network system voltage. The generating unit requirements to FRT/LVRT applied to the UK Supergrid (above 200 kV) networks have been recently updated and its requirements are [1,7,10]: (i) short circuit faults on the onshore transmission system up to 140 ms in duration: generating units must remain stable at every moment and always connected to the transmission system; and (ii) voltage dip duration on the onshore transmission system greater than 140 ms in duration: the actuation of generating units need to obey the voltage against duration profile indicated by Figure 4, and disconnection from the grid is not allowed above this profile. The requirements to offshore generating units withstanding voltage dips are also specified in GB Grid Code (for details, refer to [10]).…”

An intelligent strategy for hybrid energy system management

“…The EMS has to take account, in addition, that each energy sources provides energy at different costs. In addition, if the HES is connected to the grid, the EMS have to do its management according to the grid code [5], in addition contributing to the grid stability and providing system-wide cost and performance efficiencies.…”