Battery Charger (BCHG)
125. In Diagram 20 BCHG is the Battery Charger.
A. The Electric Current Generator (GEN) supplies a three phase voltage to BCHG.
B. BCHG produces 6 rectified voltages that are used to charge the 6 Batteries (BAT). They can for example be 6 x 48V.
C. The Battery Charger (BCHG) also produces charging current to the Batteries that supply the low voltages to the electronics. The connections are called LEPS. The reason for the separate path to the electronics is that, due to unknown material weaknesses, high power circuits are more likely to develop faults than low voltage low power circuits.
D. The circuit design used to connect the electric current generator to the batteries means that the system does not switch between generator and battery power. The Power Supply (PS) circuit will get the energy it needs either from the batteries or the generator, depending on which of the two can supply the higher amount of energy. Diodes are placed at the input of the charger to ensure that energy is not fed back from the battery into the generator.
E. GF is the low voltage tap of the generator frequency. It is connected directly to the Main Signal Processor (MSP). All other parameters and measurements are transported between the Battery Charger (BCHG) and the Main Signal Processor (MSP) over the serial connection BCHG-SL. That means that it contains a Component Controller with as many General Purpose Digital Interfaces GPDI) as is required.
F. In it's minimal form, the Heat Engine and Electric Drive combination do not need the Main Signal Processor. In that case VCTRL is the DC control voltage that controls the opening at the input of the Turbine (TB) that is connected to the Generator (GEN). In the Solar Heat Engine (SHE) drawing, the control valve that is explicitly specified as being controlled by VCTRL are Dir-V1 and B-V1 . The opening of those valves are set by the Ignition (IG) voltage so that the generator will run at it's nominal voltage and frequency after the ignition switch is turned on. Soft start is built in. When current is first drawn from the output of GEN, there will be a drop in the frequency. The VCTRL voltage will also drop and that will allow more voltage from the ignition switch to reach the amplifier that is providing the position setting for the associated valve. The said amplifier will increase it's output and thereby increase the opening of the valve. If the frequency of GEN increases above it's specified value, the voltage VCTRL will increase and the amount that it has increased will be subtracted from the Ignition (IG) voltage, which will cause the valve in question to close accordingly and reduce the frequency of the Generator (GEN) back down to it's correct operating value. The other valves in the Heat Engine are controlled by temperature and pressure. They are not part of any extra action that is required by a Man Machine Interface.
G. If a General Purpose Digital Interface (GPDI) is used to measure the VCTRL voltage, the values can be passed to the regulator that is in the valves as a digital value and an analog value. That allows the valve that receives the values to see that they are correct, before they are used.
Example: If a relevant error occurs on either the digital or analog signal paths, the controller in the valves will be able to ignore the input and shut down the valve, because it is also using a GPDI to carry out the valve position adjustments. If only one signal path is used the component controller would be making assumptions about the signal values that it receives, not decisions.
In this electric vehicle description, the battery charger converts electric power and voltage from a turbine driven generator to suitable battery charging and levels that are required. It can also bypass fully charged batteries and supply electric current directly or in parallel with the batteries to electric circuit components.
How a Solar Heat Engine battery Charger Works