ADVISOR 2

For efficient operation these two parameters should be set such that the minimum discharge and minimum charge resistances of the energy storage system fall between cs_lo_soc and cs_hi_soc. The powertrain controller will work to maintain an SOC equal to the average of cs_lo_soc and cs_hi_soc. See Figure 1.

Represents the addition power requested from the fuel converter to charge the energy storage system. The powertrain controller tries to maintain an SOC equal to the average of cs_lo_soc and cs_hi_soc. To achieve this, additional power is requested from the fuel converter that is equal to, cs_charge_pwr*((0.5*(cs_lo_soc+cs_hi_soc))-(actual SOC))/(0.5*(cs_hi_soc-cs_lo_soc)) to be used to recharge the energy storage system. As a result; when actual SOC = cs_lo_soc, cs_charge_pwr*1.0 is requested; when actual SOC = cs_hi_soc, cs_charge_pwr*-1 is requested;

and when actual SOC equals the average of cs_hi_soc and cs_lo_soc, nothing is requested. Typically, the lower this value is set the better the resulting fuel economy will be. However, if the cs_charge_pwr is set too low, the vehicle will not be charge sustaining over certain drive cycles. Also note that if no effect is observed while adjusting cs_charge_pwr parameter, the cs_min_pwr parameter (see below) may be set high enough that it is overriding the effects of the cs_charge_pwr parameter.

Defines the vector of allowable speeds of the genset (fuel converter/generator) and is determined based on the fuel converter and generator efficiency maps. This vector is automatically generated and adjusted when any changes are made to the generator or fuel converter parameters and should not needed to be edited by the user.

Defines a vector of genset (fuel converter/generator) output powers corresponding to the speeds defined by cs_spd. This vector is determined based on the fuel converter and generator efficiency maps and is automatically generated and adjusted when any changes are made to the generator or fuel converter parameters. It should not needed to be edited by the user.

Defines the initial state of the fuel converter (0 è off, 1è on).Typically this is set to 0 so that the vehicle starts in an electric-only mode of operation.

Defines the maximum decreasing rate of change of the power requested of the fuel converter. The best value for this parameter will depend both on the vehicle configuration and the drive cycle. In general, the smaller the value the faster the engine will be allowed to respond to aggressive transients in the drive cycle.

Defines the maximum increasing rate of change of the power requested of the fuel converter. The best value for this parameter will depend both on the vehicle configuration and the drive cycle. In general, the larger the value the faster the engine will be allowed to respond to aggressive transients in the drive cycle.

Defines the minimum time the fuel converter must stay off once it is turned off by the control strategy. It is only overridden if the SOC drops below the cs_lo_soc value. Typically, a shorter time will result in improved fuel economy. However, a shorter duration may also produce an undesirable on/off cycling pattern.

Defines the minimum power requested of the fuel converter. A higher value will typically force the fuel converter to operate in high efficiency region. However, it may also provide more power than is needed. See Figure 2.

Defines the maximum power requested of the fuel converter. Typically set to the highest power available in the fuel converter. However, depending to the specific fuel converter it may be beneficial to set this to a value lower than the highest power to avoid low efficiencies at extremely high power output levels. See Figure 2.

For efficient operation this parameter should be set to a value approximately equal to the lowest SOC corresponding to the minimum charge/discharge resistance of the energy storage system module. See Figure 3.

This parameter should be set slightly higher than the cs_lo_soc. More specifically, it should be set to a value less than the SOC at which the either the charge or discharge resistance increases dramatically. For efficient operation, both the minimum charge and the minimum discharge resistances should lie between the cs_hi_soc and the cs_lo_soc. See Figure 3.

Defines the additional torque requested of the fuel converter to maintain an energy storage system SOC between cs_lo_soc and cs_hi_soc. The parallel control strategy tries to maintain an SOC equal to the average of cs_lo_soc and cs_hi_soc. To accomplish this, it requests an additional torque from the fuel converter equal to, cs_charge_trq*((0.5*(cs_lo_soc+cs_hi_soc))-actual_SOC) to be used to recharge the energy storage system. Ideally this value should be set as low as possible because it acts as additional load on the fuel converter. However, below some value, the vehicle will no longer be charge-sustaining during operation on certain drive cycles. The Highway Fuel Economy Test cycle (CYC_HWFET) using the delta SOC correction can be used to verify that this value is high enough in many cases.

Below this vehicle speed the vehicle will operate as a pure electric vehicle, above this speed the fuel converter will be used as the primary power source. Typically, the lower this speed is set the better the efficiency of the vehicle. Nearly all battery power is derived from the fuel converter in a parallel vehicle. Thus setting this value to a higher speed causes the batteries to be drained to a greater extent, only to be recharged by the fuel converter. Setting the value lower forces the fuel converter to be the primary power source more often and results in better overall efficiency. However, if emissions are of interest then operating more often as a pure electric maybe of more importance.

Represents the fraction of max torque at each speed at which the engine should turn off. This parameter should be set to a value equal to the fraction of max torque at each speed at which the fuel converter efficiencies begin to drop dramatically. See Figure 4.

Represents the minimum fraction of max torque at each speed that the engine will operate at when lower torque fractions are requested. This parameter is typically set to a mid to high value (0.5-0.8) in order to force the fuel converter to operate in a high torque region of its efficiency map. IC engines quite often are most efficient at torque output levels near their max torque at a given speed. See Figure 4.