Cod. Documento: RT a Title: Fimer Plant Controller Description. Rev. Data Redatto Approvato S.Sidoti A.

Transcription

1 Pag 1 di 19 SCOPE The main purpose of the Fimer Plant Controller is make possible to the Grid Operator both remote and local control capability over an entire PV plant from a single control point The Fimer Plant Controller is capable to automatically drive the operations of several inverters of a photovoltaic plant in order to maintain the desired working setpoints of Pmax, Q or Cosphi DEFINITIONS MV Medium Voltage LV Low Voltage PV Photovoltaic POC Point of Connection PRCS Provider (Grid Operator) Remote Control System FPC Fimer Plant Controller

2 Pag 2 di 19 BLOCK DIAGRAM AND SYSTEM DESCRIPTION Below a block diagram scheme that shows how are performed these regulations: A typical installation where a FPC is present relies on the following elements: a TCP/IP network connection between all devices a Provider Remote Control System (PRCS) that dispatch commands at plant level a Measurement System installed at POC a group of Fimer inverters to be driven according to remote or local commands The FPC that acts as an intelligent link interface between the PRCS and the PV plant

3 Pag 3 di 19 TCP/IP network connection It constitutes the nervous system through which all components of the system can interact with each other Provider Remote Control System From the FPC point of view, the PRCS is a Modbus TCP/IP data link Through this data link the FPC receives commands to drive the entire PV Plant, sends commands acknowledge and also some plant measurements back to PRCS The FPC can also operate without the presence of a PRCS, allowing an operator to locally control the PV Plant Measurement Systems To make the whole PV Plant (ie all the inverters) works at the correct setpoint(s), the FPC needs a direct feedback of its action from the field This feedback is provided by a measuring device that, through a Modbus TCP/IP data link, allow the FPC to know at POC the real energy supply conditions in terms of active power P, reactive power Q, Power Factor, Frequency, voltage and current levels, ecc By means of the measurement systems, the FPC is able to verify and precisely match the setpoint required from the PRCS (or by a local operator) despite the presence of elements such as transformers, long cable connections, etc between the inverters terminals and the POC Fimer Inverters In addition to being the driving force of energy production, Fimer inverters are the real executors of local and/or PRCS commands through the FPC intermediation The Inverters are capable to precisely control grid parameters (P, Q, PF, etc) at their terminals but cannot see what s going on at POC because of cables, transformers, filters, etc To avoid a mismatch between desired and real values at POC, it s necessary to implement a system capable to adjust the inverters action, allowing them to compensate the change effects between their terminals and the POC To make this possible, Fimer Inverters are capable to receive and execute setpoint(s) commands through a Modbus TCP/IP data link, allowing them to became slaves of a Master Device (the FPC) whose purpose is to apply a common plant strategy Fimer Plant Controller The Fimer Plant Controller itself is a Panel PC (touch screen, fanless, solid state hard disk) that runs a specific control software It features two Ethernet interfaces used to communicate with the inverters, the measure instruments at the point of connection and the Provider Remote Control System (PRCS) FPC acts as the brain of the entire system Its main goal is to receive setpoint(s) commands from a PRCS (or alternatively from a local operator), allocate task to each single inverter, verify the commands execution at POC level by means of the measurement system and take actions to eliminate possible execution erros To achieve this functionality, FCP implements PI closed loop regulators (with setpoint feed forward capability) to independently control Q and PF, while the maximum power limit setpoint is simply redirected and managed at inverter level

4 Pag 4 di 19 FIMER PLANT CONTROLLER SW DESCRIPTION This section provides a walkthrough of the application running on the Touch Screen of the Plant Controller The first screenshot, the Home Page (Figure 1), is displayed once the Touch Screen has been powered on Displayed fields: Figure 1 Initial screenshot OnLine Inverters: shows the number of inverter with which the FPC established communication Remoted Inverters: shows the number of inverters working under the control of the FPC Active Inverters: shows the number of inverters currently producing energy Total Inverters kw: is the instantaneous total amount of active power produced by the inverters Total Measures kw: is the instantaneous total amount of active power measured at POC Total Inverters kvar: is the current total amount of reactive power exchanged by the inverters Total Measured kvar: is the current total amount of reactive power measured at POC Measures cosφ: displays the instantaneous power factor value measured at POC

5 Pag 5 di 19 At the Home Page screen bottom there are two icons and the system date and time By pressing the Tools Icon on the right the user may access the Command page where commands may be issued to the entire plant, by pressing the Gear Icon on the left, instead, the user may access to the FPC Configuration page By touching the three buttons MV Measures, Active Alarms and Inverter Status the corresponding pages will be respectively displayed Some pages and some parameter/setpoint values are password protected: to gain access to such pages and or gain permission to change these values you need to input the correct password using the pop-up login window and keyboard as displayed in figure 2 Figure 2 Password input Touch the Input Panel keys to input the password and confirm with the Return Key or abort the input operation using the Esc key You can also edit the value using the common keys (backspace, moving arrows, etc) This procedure applies to all the input fields of all the windows of this application To modify/change a field simply touch it

6 Pag 6 di 19 A touch on the Tools Icon of the initial window (Figure 1) brings the user to the plant controller commands window (Figure 3), however to prevent accidental setpoints changes the user must enter a password (Figure 2) to access this page if not already entered Figure 3 Plant Controller Commands The button All inverter ON allows the user to send a power-on command that will be executed by all inverter currently in remote command mode Similarly the All inverter OFF will cause to power-off and go in standby mode all the remoted inverters The user can switch between two working modes touching on the Local/Remote button (what displayed depends on current operating mode) When in local mode the plant controller applies the setpoint values directly set by the user (the left brown background group) To change a local setpoint, the user simply has to touch the desired value and an input panel will be shown (see page 5 and figure 2 for detailed instructions) In remote mode the plant controller applies the setpoints supplied by the PRCS (shown in the right brown background group) These values cannot be changed by the user As shown in figure 3, the local mode is selected and the corresponding group of setpoint values are displayed in yellow, while the remote group on the right is grayed

7 Pag 7 di 19 The setpoint values the user may specify are: Cosφ request: the desired power factor of the entire plant The corresponding checkbox allows the user to switch the entire plant in cosφ regulation mode (mutually exclusive with the following Q request mode checkbox) Q request: Is the desired amount of reactive power (expressed in kvar) that the entire plant must exchange with the grid The corresponding checkbox (mutually exclusive with the Cosφ request checkbox) allows the user to put the FPC in Q regulation mode P limit: the upper limit of the active power expressed in % of max plant power -1 means function disabled Q offset: If, for whatever reason, the communication between the plant controller and the measure instruments at the Point of Connection is lost, the plant controller no longer has feedback about the total plant exchange of reactive power (Q) In such event the FPC rises an alarm and switches to a backup strategy: the total sum of Q inverter measures is taken as feedback for regulation and the Q offset parameter (normally grayed ie disabled) takes effect (becomes yellow) adding the specified value to the current Q setpoint (both local or remote, depending on current working mode)

8 Pag 8 di 19 The button MV Measures of the initial window (Figure 1) opens the window Plant Controller MV Measures (Figure 4) Figure 4 Plant Controller MV Measures All the main information about the plant status are displayed in this window: The current I1, I2 and I3 (ampere) The Y voltages U1, U2 and U3 (volt) The delta voltages U12, U23 and U31 (volt) The total active power (kw) The total reactive power (kvar) The frequency (Hz) of output current The value of the Power Factor cos(φ)

9 Pag 9 di 19 The button Active Alarms of the initial window (Figure 1) displays the events actually present and also the already expired but not yet acknowledged events recorded by the Plant Controller (Figure 5) The information logged are the following: Figure 5 Active alarms log Description of the event occurred Timestamp of the event beginning Timestamp of the event end Alarm Status (red icons are for critical events, yellow for warnings, green for information) Timestamp of the event acknowledge The user can scroll the list by mean of the buttons Page Up and Page Down, he can also either acknowledge each event individually (button Acknowledge ) or acknowledge all events at the same time (button Global Ack ) Once an event has been acknowledged the related icon changes (red to yellow, yellow to blu) and, if the event is still present, it will be preserved in the list of active alarms until it will expire Once expired, an alarm/events will be moved in the History List that can be displayed by pressing the button Show History The button Exit close this window and go back to the main screen

10 Pag 10 di 19 The button Inverter Status of the initial window (Figure 1) opens the window Plant Controller Inverters Status (Figure 6) Figure 6 Plant Controller Inverters Status In this window the user has a more detailed view of the operating status of each inverter Each displayed line, reports to the user the following informations about a single inverter: Inverter: Inverter name/number, R/L (green remote/red local) control status, standby (red Off) or generating (green On) status If an inverter is in remote control, it can be turned on (generating) or turned off (standby) by the user simply by touching the On/Off field (a password is required to perform this operation, see next section) kw: the currently amount of active power injected by the inverter kvar: the currently amount of reactive power exchanged by the inverter Modules: the currently number of power modules switched on Plim %: current active power limit (% of inverter max power) imposed by the FPC (-1 = no limit) Qreq kvar: current reactive power request imposed by the FPC Cosφ Req: current power factor request imposed by the FPC The number of lines displayed depends on the number of inverters and can be split across multiple pages accessible using the buttons and

11 Pag 11 di 19 A mouse click on the Gear Icon of the initial window (Figure 1) brings the user to the plant controller settings window (Figure 7), however to prevent accidental configuration changes the user must enter a password (Figure 2) if not already entered The parameters that can be set are the following: Figure 7 Plant Controller Settings window Inverter Number: the number of the inverters controlled by the FPC Cycle Time: the time delay expressed in deciseconds, between each inverter polling dq kvar/min: value of the slope used when the FPC changes the Reactive Power setpoint Q Kff: Feed Forward gain factor of FPC Q regulator CheckBox: Check to use cos(φ) regulator to manage cos(φ), otherwise Q regulator is used Q Kp: Proportional gain factor of FPC Q regulator Q Ki: Integral gain factor of FPC Q regulator Cosφ Kff: Feed Forward gain factor of FPC cos(φ) regulator Cosφ Kp: Proportional gain factor of FPC cos(φ) regulator Cosφ Ki: Integral gain factor of FPC cos(φ) regulator

12 Pag 12 di 19 When the user clicks on a whatever numeric field in order to change it, a specific window is displayed (Figure 8) The user must confirm the value just entered clicking on the ENTER key or he can abort the current operation clicking on the ESC key He can also edit the value using the common keys (backspace, moving arrows, etc) This applies on all the numeric fields of all the windows of this application Figure 8 Numeric data input

13 Pag 13 di 19 The Scaling button, in the Plant Controller Setting page (Figure 7), opens a window (Figure 9) where the user can set installation dependent scale factor for: data acquisition from the measurement system ( Measure column) data exchange between FPC and the Provider Remote Control System ( Remote Control column) Once the user has modified the scale settings according to his needs he has to click on the Home icon on the right to make the changes effective, now the plant controller settings are displayed (Figure 7) Figure 9 Plant Controller Scaling Settings window

14 Pag 14 di 19 The Remote Control button of the Plant Controller Setting (Figure 7), displays a window where the user can customize the data exchange between FPC and the Provider Remote Control System (Figure 10) Figure 10 Plant Controller Remote Control window Remote Control Alive Check Enable: enables a continuous monitoring of the communication between the FPC and the Provider Remote Control System Enable Default on Communication Loss: When checked if a communication loss occurs between FPC and the Provider Remote Control System, the FPC will apply a default set of setpoints, otherwise the last received setpoints wil be maintained The remaining three parameters represent the default setpoint values to be used in case of communication loss (if Enable Default on Communication Loss checked), the user can set the values as described in the Figure 4 The user has to click on the Home icon on the right to make the changes effective, now the plant controller settings are displayed (Figure 7)

15 Pag 15 di 19 The button Save of the Plant Controller Setting (Figure 7), when pressed, stores all the plant controller settings in the system hard disk, data saved are maintained in case of power-off The figure 11 shows the Save complete message displayed when all the data have been saved Figure 11 Plant Controller Parameters save settings

16 Pag 16 di 19 The button Load of the Plant Controller Setting (Figure 7), when pressed, writes all the plant controller settings with the configuration values read from the system hard disk, this way let the user to restore the last configuration saved The figure 12 shows the Restore complete message displayed when all the parameters have been set with the stored values Figure 12 Plant Controller Parameters load settings

17 Pag 17 di 19 Fimer Plant Controller Blocks Scheme Figure 13 Overall scheme

18 Pag 18 di 19 Figure 14 Reactive Power and Cosφ setpoints detail

19 Pag 19 di 19 Figure 14 Reactive Power and Cosφ regulators detail