TACTICAL VEHICLE TO GRID AND VEHICLE TO VEHICLE DEMONSTRATION

The roll-up roll-away Tactical Vehicle-to-Grid / Vehicle-to-Vehicle (V2G/V2V) system provides a plug-and-play, very fast forming, smart, aggregated, and efficient power solution for an emerging (including austere) contingency base that is ready to generate up to 240kW of 208 VAC 3-phase power in less than 20 minutes. The system is designed to provide grid services (peak shaving, Volt/VAR control, power regulation, and current source mode) beneficial to emerging and mature grids (CONUS or OCONUS). The system uses vehicle Transmission-Integrated Generators (TIGs) to produce 600VDC power for use by vehicle hotel-loads (electrification) and off-board loads (tents/shelters, communications centers, or other electrical loads). Each vehicle is equipped with a Vehicle Communication Module (VCM), which provided the communication capability prior to initiation of transfer of up to 100kW of power via the J1772 SAE Combo Connector between vehicles (V2V) and/or for export power off-vehicle (V2G). This effort involves four tactical vehicles; two M1152 HMMWVs equipped with 30kW of On-Board Vehicle Power (OBVP) and two MaxxPro Dash MRAPs equipped with a 120kW 3000 Transmission-Integrated Generators (3TIGs) with V2G and V2V capability, four 60kW DC-to-three-phase (3Ø) AC power converters with 600 VDC bus distribution systems and four 22.8 kWh Energy Storage Systems (ESU). This multi-vehicle based power system utilizes variable engine speeds for efficient power generation. The demonstration project included the sub-system development, communications systems development, system integration, testing, and demonstration. The system supports host-grid connectivity to reduce deployed fuel consumption for power generation by 20 percent. This can come through operation of the engines at their optimum speed based on the engine map, along with proper management of the generation and energy storage resources. In addition, one or more generation sources can be completely turned off (i.e. engine off condition) when possible depending on the load demand, thus resulting in fuel economy improvement. The system capability was first demonstrated at TARDEC and then with the Warfighter at Fort Devens, Sustainability Logistics Basing (SLB) Science and Technology Objective Demonstration (STO/D), in FY16. The paper includes test data and results collected during the; System Validation Test at TARDEC, APG Safety Release, Demonstration at Fort Devens. In addition, the paper includes test results of sub-system and some results from modeling and simulation (M&S) of the system. M&S will involve relevant logic for deciding which VCM module acquires the status of a Master Controller, and will also include droop control of the generation sources and integration of the energy storage sources (ESU), i.e. the batteries, so that proper grid voltage level can be maintained within limited boundaries. INTRODUCTION The goal of the V2G/V2V effort is to demonstrate the capability to assemble a vehicle based power supply for austere contingency bases. This demonstration achieves this by providing 240 kW of 120/208 three phase VAC power in less than 20 minutes while achieving an estimated 20% fuel savings over conventional methods. This project implements operational energy improvements on the move and when at a base by aggregating multiple vehicles into the grid. Currently there are multiple operational energy gaps identified by the Department of Defense (DoD). Vehicles that are not on a mission can use the onboard vehicle power systems to reduce the fuel consumption for generating power at the contingency bases currently more than 50% of the Army fuel consumption supports power generation. Data shows that intelligent power distribution and management systems that aggregate power generation sources and manage prioritized loads reduce fuel Proceedings of the 2016 Ground Vehicle Systems Engineering and Technology Symposium (GVSETS) DISTRIBUTION STATEMENT A. Approved for public release; distribution is unlimited. 2 consumption by more than 20%. Data shows that vehicles are not on missions 95% of the time; the demonstration will show that the vehicle’s capability can be utilized when not performing on any missions. Vehicles with V2G capability can intelligently and securely contribute to the FOB’s power grid and reduce fuel demand through use of the stored energy on the vehicles. OVERALL SYSTEM The system uses vehicle 3000 TransmissionIntegrated Generators (3TIGs) to produce 600VDC power for use by vehicle hotel-loads (electrification) and off-board loads (tents/shelters, communications centers, or other electrical loads). This effort involves four tactical vehicles; two HMMWVS equipped with 30kW of On-Board Vehicle Power (OBVP) and two MRAPS equipped with a 125kW 3000 TransmissionIntegrated Generators (3TIGs) with V2G and V2V capability, four 60kW AC to DC power converters with 600 VDC bus distribution systems and four 22.8 kWh Energy Storage Systems (ESU). Each vehicle is equipped with a Vehicle Communication Module (VCM), which provides the communication capability to transfer up to 100kW of power via the SAE J1772 Combo Connector between vehicles (V2V) and/or for export power off-vehicle (V2G). Figure 1: System Diagram VEHICLE DESCRIPTION DRS Technologies provided two OBVP-equipped MRAPs (80kW-capable, equipped with 125kW) and two OBVP-equipped HMMWVs (30kW-capable). The 3200MSG OBVP system in the MRAP, Figure 2, is a product of DRS and Allison Transmission Inc. It consists of an Allison 3200SP transmission with an integral 125kW Permanent Magnet Machine (PMM) built by DRS. A power electronics assembly, the Generator Controller Bus Regulator (GCBR), uses a switching regulator to manage the PMM and to generate the highly regulated 600 VDC bus used as the microgrid power source. Previous TARDEC testing of this OBVP system showed the average efficiency to be 93%. Figure 2: MaxxPro MRAP Equipped with DRS/ATI 3200MSG 125kW OBVP System The HMMWV OBVP system is a product of DRS; 30kW PMM mounted between the engine and transmission in a sandwich configuration, DRS PMM control and regulation electronics and a 30kW 208 VAC inverter. DRS removed the inverter for this project and replaced it with a 400VDC – 600VDC converter to bring it to the same bus voltage as the MRAPs and compliant with MIL-PRF-GCS600A. Figure 3: M1152 HMMWV Equipped with DRS 30kW OBVP System All vehicles were modified for remote start – stop. The remote start is triggered from CAN (standard J1939) commands from each vehicle’s VCM when the voltage droop is detected on the 600V bus. Remotestarting occurs when electrical load demands exceed power generating capacity of the vehicles currently supplying power at the time the load excess occurs. This keeps the overall system operating at optimal (peak) efficiency. The HMMWVs were further updated with a TARDEC – supplied throttle actuator control (described below) that allows the remote start-stop control network to use the vehicle throttle to vary the amount of power supplied to the microgrid. This function was implemented on the MRAPs by the use of CAN bus commands to the vehicle engine control module (ECM) that cause the idle speed to transition between pre-defined steps. Proceedings of the 2016 Ground Vehicle Systems Engineering and Technology Symposium (GVSETS) DISTRIBUTION STATEMENT A. Approved for public release; distribution is unlimited. 3 Throttle Actuator Control The system uses a stepper motor driven by an Hbridge circuit. The system responds with a position sensor and the logic controls the mechanical linkage from the fully closed position to the fully open position. The stepper motor is also available to control the position using CAN messages, which are included below but for the purpose of this demonstration the Hbridge was used. Software Controls The software reads the following parameters to control the vehicle to the desired position: • Engine Speed (Picked up off the transmission speed sensor) • Stepper Motor Position (Fully extended = 0% Throttle and Fully Closed = 100% Throttle) • Requested Engine Speed (Generator Controller Desired Engine Speed) Using these variables the logic will arbitrate on how it commands the desired stepper motor position. Drivers Stepper Motor Position The logic was designed to override the drivers throttle position for testing purposes and for test cell uses. This allows the greatest flexibility with testing and usage cases. The logic using calibrations allows the user to request throttle via CAN (Test cell case), INCA (calibration), and throttle hardware. Once the source is determined, the logic will convert the desired throttle position to a desired stepper motor position using a calibration table. The speed request logic from CAN will need to be updated with enable conditions to verify the request, the vehicle is stationary, and the vehicle transmission is in park or neutral position. These details can be quickly added in the future based on available CAN messages. Stepper Motor Commanded Position Controls Based on the drivers and speed requested stepper motor positions the logic will control to the largest position. The logic uses the H Bridge circuit and the position feedback to control the stepper motor to the correct position changing the magnitude of the request based on the position error. This allows for optimal controls and limits overshoot. As seen in Figure 4, a step request from the throttle (red) results in a response time around 0.6 seconds from 0 to 100% and back to 0% from 100% (grey). Figure 4 Stepper Motor Commanded Diagnostics The control logic has a secondary circuit to drive the stepper motor back to the idle (0%) position in case the absolute error in the commanded position is greater than a diagnostic delta for a calibrate-able period of time. In the case the motor does not return to idle (i.e. blown fuse), the logic sets a fault and changes the settings on the relays to switch to a low side dr