Power Supply (PS)

126. In Diagram 20, the Power Supply (PS) is used to generate the three phase voltage that is required in order to drive the type of motor that has been selected for electric vehicle operation as described in this text.
       
A. The Main Signal Processor (MSP) communicates with the Power Supply (PS) over the PS-SL serial communication line.

B. The electric drive motors are synchronous motors. The Gas Pedal (GP1) signal is used to  set the frequency of the Voltage Controlled Oscillator (VCO) in the Power Supply (PS). The Gear Lever (GL1) signal is used to select the rotor resistance of the electric motors so that the current will be limited according to the amount of inertia that is expected at each gear position. At this point in this text it is stated here that in this concept, the electric vehicles do not need the Component Controllers or Main Signal Processor in order to make the electric motors function.

C. The Gear Lever Signal (GL1) is used to switch the range of the VCO so that it will oscillate within the range required for each gear.  The Gas Pedal (GP1) signal is used to vary the frequency of the VCO with in the range defined by the Gear Lever (GL1) signal.

D. The output of the VCO passes through the frequency divider DIV. It's division factor can be controlled by the MSP. The capability of the MSP to partially control the output of the VCO and the frequency divider DIV allows object avoidance functions to be implemented in the electric vehicle being described in this text.

E. The VCO can be replaced by a quartz which is connected to a Gas Pedal frequency divider. The output of the Gas Pedal divider is connected to a Gear Lever divider. The output of the Gear Lever frequency divider is connected to the Three Phase Encoder (ENC).

Example:
I. When the vehicle is put into first gear, it's Gear Lever Divider will have a division factor that represents the maximum frequency for the specified maximum speed, but it will not receive any clock pulses, from the Gas Pedal Counter, because the Gas Pedal (GP) value is zero while a gear is being changed.    
                            
II. When the driver presses the Gas Pedal (GP) the Gas Pedal divider will start pulsing the input of the Gear Lever divider according to the division factor translated from the GP voltage level.

III. As the value coming from Gas Pedal (GP) increases, the number of pulses going from Gas Pedal divider to the Gear Lever divider will increase, because the division factor of the Gas Pedal divider will be reduced accordingly. The division factor of the Gear Lever divider will not change.

IV. That means that while a vehicle is changing gear the frequency and amplitude of the UVW voltage will be zero, because the Pulse Width Modulator (PWM) in the said Power Supply (PS) circuit will only have an output, if an alternating voltage is at it's input.

V. After the gear has changed up to the next level, the UVW voltage will be turned back on again at a frequency that is very close to the one that existed, before it was turned off. The component controller will know what that value is, because it reads that value from the register of the GPDI that receives the GP1 value from the Man machine Interface. In such a case the component controller in the Power Supply (PS) will act as a peak value detector that can store the last maximum positive going peak value and know which new value to set for a new Gas Pedal value. It will check the speedometer value and potential energy that is in a vehicle, before it makes the decision.

VI. When the gear change is in the downwards direction, the value of the Gas Pedal (GP) is ignored by the Gas Pedal Counter, until it has scaled itself down to the value that represents the new Gas Pedal (GP) value, or until the potential energy that is stored in the movement of the vehicle is used up.
  
F. The output of ENC is a three phase signal that is integrated by the function block ITG and filtered by BP, before it is passed on to the Voltage Controlled Amplifier (VCA). The Gear Lever (GL1) voltage sets the center frequency of the Band Pass (BP) so that it matches the center frequency of the VCO. The Gas Pedal (GP1) voltage varies the frequency of the VCO around the value set by the Gear Lever (GL1) voltage. The Voltage Controlled Amplifier (VCA) can take on positive and negative values, but in reference to the UVW voltage it is still fail safe, because a missing half cycle will only mean a reduction in output power.        

G. The output of the VCA controls the Pulse Width Modulator (PWM) that produces the high energy UVW voltage that is passed on through the Clutch + Brake Power (CBP) section of the circuit.

H. The GL1 and GP1 voltages from the Man machine Interface (MMI) as well as the ITG frequency from the Power Supply (PS) are used to drive the Synthesizer (SY) so that electric road vehicles will produce audible sounds that represent their speed or state.

I. The RV1 signal voltage from the Man Machine Interface (MMI) to the Power Supply (PS) is used to reverse the direction of the electric motors by reversing the phase of the UVW voltage. The same RV1 voltage is used to limit the frequency of the VCO and band width of the BP so that the maximum reverse speed of the vehicle is also limited.









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Page 13   Preface
The Power Supply is used to provide the power voltages that are required by the electric motors and other actuators in an electric vehicles.