[Weter]

Great description! Thank You, Jan.

Quote

the settings of the traction motors redundant relays

I guess, overload(-protection) relays were mentioned there.

Well, this is indirect non-automatic commutation scheme, with optional field weakening.
Driver fully controls small current signals in control circuits, according to ammeters readings, and these signals then control power circuits contactors (most large of which are electro-pneumatically actuated) these latter are switching large currents in power cirquits of traction motors.

[Weter]

I'm thinking, how to simply explain the current and the voltage spreading in circuitry between plus (contact wire) and minus (rails).
Let's say, voltage spreads along the conductor, while current spreads across. In longer circuits, voltage drop is more smooth, in thicker circuits current is less dense. Higher voltage drop causes greater current and greater current causes bigger voltage drop in the same conductor, while greater resistance will reduse current, but increase voltage difference.
The formula, describing these dependencies is known, as Ohm's law:
I=U/R (or U=IR or R=U/I)
where I is current, U-voltage, and R - resistance. Power will be U times I
As a result, when four motors connected one by one (in series), the voltage is being divided between them, as 1/4. Which means, power is being divided too.
It's important, that current is the SAME along entire circuit, while voltage gradually drops between motors from maximum to minimum. Total voltage is the sum of voltage drops on every component of the circuit and will be greater on components with greater resistance.
Taking in account above statements about "counter-current" and "saturation", caused by it, it's clear, that given voltage on every motor's terminals will be a limit for maximal power, which is able to be produced.
Resistors (sometimes called in Greek "rheostats") are used for avoiding dashes, while motors being turned on and off: they are being inserted in series with motors, so they provide additional voltage drop (increase of circuit's length). They are sectioned, so can be inserted or excluded gradually, but, as Jan just have mentioned, the voltage drop there is being achieved by dissipating some (significant) part of electric power as heat. And this inefficiency is a great disadvantage of DC contractor-controlled systems.

[Weter]

For producing full power, we need to increase the voltage drop on every motor's terminals.
To do that, we will connect every motor (or pairs of motors, still being connected in series) inbetween plus and minus, so we'll have a number of parallel circuits now.
The voltage will be equal on every terminal, connected together, so, as circuits will become "shorter", containing only one (or two) motors, instead of four, it's drop on every motor will now be full (or half) of line voltage (I.e. between wire and rails), and motors will be able to produce much more power, as greater voltage will allow greater current to pass motor coils.
What for current, it will spread between these parallel branches, and will be greater in "thicker" circuits (i.e. those, which have less resistance). The total current will be the sum of currents in every branch, so power consumption of locomotive will grow, sinse it will pass more current.

Let's revise field weakening now (as we already have seen, it helps to shift motor's "saturation" speed to greater values).
It have proven itself - to use on locomotive such motors, when rotor and stator coils are connected in sequence (they are better self-controlling, however tend to accelerate in crazy way, in case of adhesion loss: irrecoverable wheel slip will be result). So full current will flow through rotor, but only part of it will be passed through stator, when it is being bypassed by resistor, during field weakening. Bigger current causes bigger voltage drop along the circuit with same length, and bidder voltage drop, as it was said above, will give more power output.

For smoothing the growth of torque, being produced in parallel arrangement, after serial one, rheostats are used again, allowing to increase/decrease voltage drop on motors gradually, as it was explained above. They are inserted/excluded in series with motors, taking part of voltage drop on themselves again, by dissipation of some amount of power as a heat.

[Fablok]

Ok here electric schemes of current circuits. Sorry for my little mistake non resistant on series is position 28 ( not 29 ) and for parallel is 43 ( not 44 ). Use translator to check shortcuts names from first screen ;)

https://i.ibb.co/F478pRj/leg.jpg

Main Circuit

https://i.ibb.co/qNVfjq4/og.jpg

1st position

https://i.ibb.co/gtq1Txz/1.jpg

28th position

https://i.ibb.co/yh1Vj0d/28.jpg

28th positiont shunt position 6 (max)

https://i.ibb.co/gzksPR2/286.jpg

29th position

https://i.ibb.co/3dnMfNR/29.jpg

43 position

https://i.ibb.co/1T4m7YW/43.jpg

43 position 6 shunt (max)

https://i.ibb.co/54xMSTc/436.jpg

[Weter]

Good.
See also

What is most important, now we see the place, taken by mentioned two ampermeters (MP1 and MP2) in scheme!
So, MP1 shows current only when parallel arrangement is on, MP2 - always.

Are SWO1-SWO4 fan-motors?

[Fablok]

Yup. EU07 have 4 vents for 2 sets of resistor box. 2 for one box. Motors ace colled via air flow from below of loco and from ducts witch are connected to converters. Loco have 2 converters. 2 air channels from one converter.

Here one of vent. And this is legendary sound of starting Polish electric ;)

https://www.youtube....h?v=yxN8IMHs904

[Fablok]

There are two main electrical circuits in these types of locomotives. HV (high voltage) circuits, i.e. those that are supplied with the voltage from the traction network, and LV (low voltage) circuits, i.e. those that are supplied with 110V DC on-board voltage. The on-board voltage is generated by the main converters supplied with voltage from the HV circuit, and in the absence of HV power supply or the converters are turned off, the LV circuits are powered by the accumulator battery, which is charged by them during normal operation of the converters.

The HV circuits include:
- HV main circuit, i.e. power supply circuit for traction motors,
- HV auxiliary circuits, which are divided into:
- circuits of main converters,
- driver's cab heating circuit
- trainset heating circuit


The LV circuits include:
- LV auxiliary circuits, which are supplied from the main converters, are divided into:
- converter circuits
- main compressor motor circuits,
- control circuits of motors of starting resistance fans,
- battery circuit,
- auxiliary compressor motor circuit,
- train heating circuit,
- driver's cab heating circuit,
- cabin stove circuit,
- high-speed switch control circuit,
- desktop ammeter circuits,
- signaling circuits,
- lighting circuits.

Rotating converters with traction motor fans:
In the EU06 and EU07 electric locomotives, two rotating converters of the MG 91H type are installed in the machinery space. These are electric machines used to convert the mains voltage into 110V on-board voltage, which is used to charge the batteries and power low-voltage on-board devices. The converter consists of a separately excited DC motor powered by a 3kV mains voltage and a separately excited generator generating 110V electricity, built on one shaft and a common body. A fan is installed on the shaft on the motor side to ventilate the described electric machine. On the generator side, the converter is integrated with the fan blower of the traction motors.


Basic data of the converter:

- engine continuous power: 30.9 kW,
- motor rated voltage: 3000 V,
- motor rated current: 12.7 A,

- generator continuous power: 17 kW,
- rated current of the generator: 155 A,

- nominal spin speed: 1310 rpm,
- fan capacity of traction motors: 204 m3/min,
- weight without fan and cover: 1660 kW,

Rotating converters with traction motor fans:
The motors of the converters are supplied from the HV circuit behind the fast circuit breaker. The circuit of the converters includes the converters' contactors, the converter's excess relay mentioned earlier, the protective resistor, the protective transformer, the starting resistor, the externally excited HV winding and the auxiliary undervoltage - current relay.
The contactors of the converters are installed in the HV 1 compartment and are used to switch on and start the converter motors. The SMA 25 contactor acts as the switching contactor, while the SMB 25 contactor is responsible for starting the converter motor. The contactors in question are made of an electromagnet drive of the main contacts and an extinguishing chamber. SMA-25 contactors are additionally equipped with auxiliary switches. The drive consists of: the electromagnet core with the excitation coil and the armature.
The SMB 25 start-up contactors are controlled by the PVJ-25 start-up relays of the converters.

The protective resistor is used to limit the short-circuit currents of the motor, reduces the starting current and mitigates the voltage changes occurring in the traction network.
The protective transformer protects the motor operation in a transient state and plays an important role in the case of large voltage drops in the catenary.
The starting resistor is used to limit the starting current. Works with contactor SRP1 and relay PRP1. When the starting current of the motor is less than or equal to 20A, the PRP1 relay closes the circuit of the starting contactor coil of the converter. This contactor, on the other hand, closes its contacts causing the starting resistor to be disconnected from the circuit.
The PPZ1 undervoltage and voltage relay protects the motor against the effects of current return after its sudden decay. Opens the starting contactor circuit and activates the starting resistance when the motor is restarted.

The excitation circuits of the converters include a non-contact voltage regulator type IRM-1/110V, which is used to stabilize the 110V voltage produced by the converter. The task of the regulator is to maintain a theoretically constant voltage value (106.5-113.5V) regardless of its rotation. Each of the converters has an independent regulator.
The timing circuits of the converters are protected with 5A automatic circuit breakers, which are located in the driver's assistant desks. The converter is switched on by the driver by switching the toggle switch on the panel.


When the converters are turned off, the power supply to the on-board network elements is provided by the accumulator battery. The battery unit is housed in two boxes, in the space between the bogies under the frame. The 4G60H type nickel-cadmium battery consists of 72 series-connected cells placed in 24 boxes, giving a total output voltage of 96V DC. The battery is charged by one of the working converters. A diode is included in the battery circuit, which acts as a reverse current relay and disconnects the battery power supply when the voltage from the generator is lower than the current battery voltage. The battery is protected by 2 Bi-Wts 60A fuses and by a 63A automatic circuit breaker, which also serves as a battery disconnector, which is located on the automatic circuit breaker panel in the driver's desk - cabin A. This disconnector turns off the battery power supply, cutting it off from the LV circuits for the duration of parking when the locomotive is idle.

[Fablok]

And here straight from the locomotive manual how to start it ;)
Before starting the locomotive, you should:

Close and lock the doors and side covers of the cabinet.
Set the knob packet switches in the following positions:
battery charging switch normally
converter selector switch 1+2
compressor selector switch 1+2
axle load compensation switch off
current range switch normal

Close the following toggle circuit breakers:
Cabin 1 (A):
battery +
battery -
pantograph compressor
inverter voltage regulator 1
Cab 2 (B):
"main timing"
inverter voltage regulator 2
unlocking the redundant relays of the auxiliary circuits
Check the battery voltage - it should be around 90V; at voltages below 80 V, the high-speed circuit breaker (HSCB) should be closed manually (in EU 06 series locomotives).
Insert and turn the key of the timing disconnect switch (CKS) in the driving cab.
Unlock all stuck relays using the appropriate impulse switches in the cab.
Activate the pantograph control circuit breaker.
Turn on the circuit breaker of the timing and sander circuits.
Turn on the circuit breaker of the starting resistance fans.
Turn the changeover cock in the machinery space to feed the pantographs from the pantograph compressor.
Turn on the pantograph compressor motor with the foot switch. The switch must be kept closed until the compressor motor is automatically switched off by the pressure switch. In EU 07 series locomotives, instead of the foot switch of the small compressor, a manual switch is installed.
Set the shut-off cock of the selected pantograph to the PANTOGRAPH UP position
After the pantograph reaches the catenary, the pantograph compressor must be switched on again using the foot switch (EU 06) or the hand switch (EU 07) to make up for air loss.
Press the impulse switch QUICK SWITCH ON on the panel in the driver's cab and check the activation - the signaling lamp should be on: QUICK SWITCH ON.
Turn on the inverter circuit breaker, the inverter should start.
Turn on the compressor circuit breaker after the inverter starts up, the compressors should run.
The pressure in the pneumatic circuit of the pantographs shall be maintained by means of the pantograph compressor until the pressure of 0.5 MPa overpressure in the main tanks is reached.
Switch on the pantograph impulse switch to override the main pantograph control valve.
Move the changeover cock in the pneumatic circuit of the pantographs to the supply from the main tanks.
Insert the travel switch directional shaft handle and move it to the desired direction.
Check the indicator lights, operation of the audible signals and lighting.
Check the operation of the brake.

Note: After entering SHP, the solenoid of the brake line filling electropneumatic valve in cabins A and B can be energized when the pressure in the brake line drops below 0.35 MPa overpressure, only after pressing the foot switch.

[Weter]

Ah, my memory get a hole: thanks for reminding about "converter" meaning.
It appears, we really need controller's position - related triggers for turning on fans (their sound) and second branches ampermeter.
manual says about scripts for definition of specific controllers... It's interesting, whether it's possible to use such scripts for said things?

[Fablok]

Vents test

https://www.youtube....h?v=wpgVfZ1fKvY

Overcharge. Typiccaly You can charge ane Polish electric up to 600A.

https://www.youtube....h?v=FF44ykqTIt0

Inverter start

https://www.youtube....h?v=r79yWYeSyjE

wheel slip

https://www.youtube....h?v=RgZrFfb4OAQ

And jet speed EU07 ;)

https://www.youtube....h?v=sZPjOZuQfVE