Megarevo MEGA Series - battery power conversion system

Description

• Device class: three-phase battery power conversion system (PCS)
• Brand: Megarevo
• Name in My Devices: Megarevo MEGA Series
• Models: MEGA0030T to MEGA0500T, 30 kW to 500 kW
• T models: grid-tied only
• TS models: automatic transfer between on-grid and off-grid, with a load bus
• Identity: model, rated power and serial number, read at the scan
• Hardware on the Info tab: T or TS, from the model name

LoggerV Connection

• Modbus address range: 1 to 247
• Scan check: the power in the model name must agree with the Rated Power register

Plant Control Functions

• Battery converter with its own grid switch:

  • Active power: register 2761, 100 W steps, no read-back
  • Actual power: the DC bus power
  • Start, standby and stop: register 2769
  • Grid mode: register 2765, On-grid to follow a power setpoint, Off-grid to form the load bus
  • Grid switch state: closed only when the grid breaker and the grid contactor are closed
  • Reactive power: not implemented

• LOMAC: forms the load bus, follows a power setpoint, disconnects itself from the grid (How LOMAC works)

The LoggerV sends no start, stop or grid mode command while Grid connected mode of PCS is Auto.

LOMAC does not use the converter while one of these conditions applies:

• Grid connected mode of PCS: Auto
• Control mode: Local
• Mode settings: not read in the last 10 seconds

While LOMAC controls the converter, a stop also sends the shutdown command to a converter that is already stopped. The converter then does not start by itself when the grid comes back. If LOMAC Enabled is off on this converter, the converter blocks off grid for its LOMAC island.

Recorded Data

• Converter Start Permission on the device page: DC-AC Converter Status
• DC Soft Start stages: Not starting, Soft starting, Complete
• Converter Run State values: Off, Soft start, Grid-ON Charge, Grid-ON Discharge, Grid-OFF Discharge, Drop and Connect, Standby, Grid-OFF Charge
• Converter Run State 2: CV Discharging or CV Charging. A value other than 0 replaces Converter Run State.
• Converter Control Mode values: Constant Power, Constant Current, Constant Voltage, Off Grid
• Reactive Power Regulation values: Disabled, Pf regulation, Q Regulation
• Alarm fields: also shown as alerts. The recording keeps alarms shorter than 5 seconds.
• Contactor faults: the two Megarevo register maps name different contactors, the grid contactor or the output contactor
• Total DC-DC Power: always 0. The driver does not fill it.
• Not on the device page: Converter Run State 2, Converter Control Mode, Grid Connected Mode (actual), the six alarm fields, Grid Apparent Power, Total DC-DC Power
• Live only: all other values, including the battery state of charge, the phase voltages and currents, and the energy counters

Reference Documents

These open in the myPower24 library. Sign in to read them.

• Megarevo MEGA series PCS user manual

Wiring

The Add-Device wizard makes the connection diagrams; see How to add a device in myPower24.

• LoggerV port: an Ethernet port for Modbus TCP, or an RS-485 port for Modbus RTU
• Factory settings password on the touchscreen: 123
• Factory RS-485 baud rate: 9600 bit/s
• Factory IP address: 192.168.1.250
• Factory subnet mask: 255.255.255.0
• Factory gateway: 192.168.1.1
• Ethernet port: an RJ45 port labelled LAN, on the rear of the touchscreen controller.

Setup

1. Connect the cable as the generated diagram shows.
2. On the converter touchscreen, open General Settings and type the settings password.
3. Set a Modbus address that no other device on the bus uses.
4. For RS-485, set the baud rate of the converter to the port Bus Speed.
5. For Ethernet, open System Settings on the System menu of the touchscreen. In the Network panel, set the IP address, the subnet mask and the gateway for the site network, then tap Apply and Restart system.
6. Add the device on the LoggerV; see How to add a device in myPower24. For Ethernet, type the IP address, the TCP port and the Modbus address. For RS-485, type the Modbus address.
7. On the device page, open Settings > Advanced Settings and set Control mode to Remote.
8. Open Settings > General Settings and set Grid connected mode of PCS to On-grid or Off-grid.
9. Set up the battery link; see Battery Communication.
10. Open Actual Data. Make sure that the AC Grid / Load / Inverter Ports values change, and that BMS Info shows SOC and Voltage.

Battery Communication

• Link: battery BMS to the converter directly, CAN or RS-485
• BMS communication mode on the converter: no communication, CAN or serial port
• Factory CAN baud rate: 250 kbps, from the MEGA user manual. The Megarevo CAN protocol documents give 500 kbps, so check the rate on the converter before you connect the battery.
• myPower24: reads the battery values from the converter over the same Modbus link. It does not set the BMS link.
• Battery values on BMS Info: BMS State, SOC, SOH, voltage, current, minimum and maximum cell voltage and cell temperature, maximum charging and discharging current, allowed charge and discharge power
• BMS State values: Battery full, Battery discharged, System Alarm, System failure, System normal

Device Page

• Info: General Info (manufacturer, device name, serial number, installed date), Version (hardware, firmware), Nameplate (model, rated apparent power, rated active power, protocol point table, screen firmware), Modbus connection
• Actual Data (opens first): PCS Status, AC Power Flows, AC Grid / Load / Inverter Ports, DC Bus, BMS Info, Temperatures, Dry Contact Status, Battery Energy Counter (AC-side)
• Settings: General Settings, Advanced Settings, Lithium Battery, Lead-acid Battery
• General Settings: Remote control on/off, Remote EPO, Grid connected mode of PCS, Working mode, Constant power (AC), Constant voltage, Constant current, Output reactive power mode, Output reactive power, Output power factor
• Healthy link: the AC Grid / Load / Inverter Ports values change; BMS Info shows SOC and Voltage
• Converter running: Converter Run State on PCS Status shows a value other than Off

Troubleshooting

LoggerV messages, during the scan or a settings change:

• "Device response with model not define as PCS. Regiseter 2000 String 10byte(5 reg) must read like 'PCS####[TS]'.Response: [...]": the converter did not send a model name. Examine the Modbus address. Make sure that the LoggerV connects to the correct unit.
• "Device response with ratedPower not equal with model ratedPower. Regiseter 2000 String 10byte(5 reg) must read like 'PCS####[TS]'. Regiseter 2659 uint16_t (1 reg) must read like '500' Response: Model[...] RatedPower[...]": the converter reports a rated power that is different from the power in its model name. The LoggerV does not add the unit. Speak to Megarevo.
• "Device response with Invalid Serial number len. Response: [...]": the serial number from the converter has fewer than 10 characters. Scan again. If the message stays, speak to Megarevo.
• "Disable LOMAC on this converter to change it.": you changed Grid connected mode of PCS or Remote control on/off while LOMAC controls this converter. Set LOMAC Enabled to off for the converter first.
• "Permission denied! Required permission [basic].": you do not have Editor access or higher to the plant.

Converter alarms, conversion stage: "Converter over current", "Converter by wave current limiting", "Converter fault", "Bus over voltage fault", "Bus short circuit fault", "Converter over temperature", "Over load", "DC contactor failure", "Converter phase loss", "Inverter over voltage fault", "AC voltage amplitude out of sync", "Bus software over-voltage", "Bus hardware over-voltage", "Hardware over temperature fault", "Carrier synchronization fault", "Device ID conflict", "Output short circuit", "Drive cables fault", "Lightning protection fault", "15V power failure", "AC fan failure", "Parallel communication failure".

Converter alarms, grid side: "Grid connected contactor open circuit", "Grid contactor short circuit", "Grid over voltage", "Undervoltage of Grid", "Power grid voltage reversal", "Frequency anomaly of power grid", "Island protection", "Abnormal insulation impedance", "CT failure".

Converter alarms, battery side: "Low battery voltage", "Battery charging prohibited", "Battery reverse fault", "Battery overcurrent", "Battery discharge is not allowed", "Battery failure", "Battery under-voltage", "Battery over-voltage", "Low battery power".

Converter alarm, emergency power off input: "EPO".

BMS alarms, sent through the converter: "Cell undervoltage", "Cell overvoltage", "Battery over temperature", "Battery under temperature", "Total voltage overvoltage", "Total voltage undervoltage", "Charge overcurrent", "Discharge overcurrent", "Single cell voltage differential pressure large", "Battery high temperature difference", "Cell SOC Too High", "Cell SOC Too Low", "Insulation Fault", "BMS internal communication failure", "BMS contactor abnormality", "BMS internal abnormality", "Emergency Stop", "Fan Alarm", "Cell Voltage Imbalance Alarm", "Cell Temperature Imbalance Alarm", "String BMS Self-disconnect Alarm", "Terminal High Temperature Alarm", "Fire Protection Abnormal", "Control Command Timeout", "Abnormal PCS State(BMS Alarm Bit)", "Abnormal EMS State(BMS Alarm Bit)", "High Voltage Interlock", "Current Leakage Error".

The BMS also sends 53 internal self-test codes: sensor, chip, memory and analog front end errors. For an alarm that is not on this page, record the code, the message and the device serial number. Send them to support.

Permissions

• Viewer: the device page and the recorded data, read only
• Editor, Installer or Full control: every setting on the Settings tab
• Advanced and OEM roles: no more access on this device

A higher level includes all lower-level access.

Tips and Gotchas

• No communication watchdog: the converter keeps the last power setpoint if the LoggerV stops. The driver writes no stop or zero setpoint when the LoggerV shuts down.
• Reactive power settings: the General Settings values go to the converter. Plant control does not send a reactive power setpoint.