SY-EPC-LPC Polarity-Switch A4 General

Power Converter Characteristics

Design & Operation Responsibles

Power Converter Architecture

Power Part

Control Part

Magnet Protection

Power Converter Components

Magnet Types

Machine Installation

Production Contract & Contact History

Power Converter Characteristics

Polarity‑Switch A4*	Polarity Switch
	* A4 → 4 circuits managed
Power In	1 ~ 230 V / 0.5 A_MAX
Output Rating	PS-A4.4x080:
	I_DC = 80 A_DC
	V.diode = 300 V _{(400 V rating)}
Control type	Specific Burndy connectors direct signals
	Optimized for FGC3 / Ethernet And direct control
	Single Interlock-type Interface

Design & Operation Responsibles

Benoit FAVRE	Responsible-1: Design
Yves THUREL	Responsible-2
Error processing SSI file	Integration

Power Unit Architecture

Polarity Switch is mainly controlled by FGC3, and protects itself against changing state at higher current than 5A.
It can also exchanges signal with Power Module and Discharge system through 2 Interlock Interfaces / connectors.

Polarity Switch can send, in case of an internal fault:

An interlock directly to the Power Supply to stop it.

An interlock directly to activate the Magnet Energy Discharge system if present to handle magnet energy.

Polarity Switch can receive an interlock freezing its powering status, ignoring any changing state command:

From the Power Supply: Powering Status signal (Power On), or DCCT 0A contact.

From the Magnet Energy Discharge system (end of discharge, status).

General Schematic General Schematic - Polarity Switch In Fault Polarity Switch In Fault - Polarity Switch Movable Conditions Polarity Switch Movable Conditions

Polarity Switch simplified Architecture .vsd

Polarity Switch Connector Pin Assignment

Signal	Pin	Cde/Status	Description
POLSWPOS_NOT	01	Status Out	01-03: closed → Current Polarity Switch Status = Positive
POLSWNEG_NOT	02	Status Out	02-03: closed → Current Polarity Switch Status = Negative
0V	03	GND
POLSW_FAULT	04	Status Out	04-06: open → Polarity Switch in fault status. POLSW_FAULT = POLSW_FAULT1 = POLSW_FAULT2 It could be related to internal power supply or too hot inner temperature.Required as soon as the unit can fall in fault (latched). This NEW signal allows the use of a intelligent Polarity Switch using internal internal faults. A high current switch could quickly be very hot in case its contactor contacts are damaged.
POLSW_LOCKED	05	Status Out	05-06: close→ Polarity Switch can be controlled to change state (output current monitored is higher than safe values). This NEW signal was added so that FGC3 can report Polarity Switch status in case the change of polarity is not allowed by the switch itself.
0V	06	GND
POLSW_RESET_NOT	07	Cde In	07-08: closed (10ms pulse) → Reset all latched faults Required as soon as the unit can fail in fault (latched). Power converter & Polarity Switch are using the same Reset_Not signal. Not a pure creation, just re-use (must travel through the connector) signal sent by FGC3 to converter and available on backplane.
0V	08	GND
Vcc	09	Pwr In	This Power line (+24 V_DC, 0.1 A_DC) is used to provide energy to relays or contactors to a "controlled unpowered" unit acting on motors only for example and without any local electronics. Required for compatibility with no-electronic management polarity switch.
POLTOPOS_NOT	10	Cde In	10-12: closed (10ms pulse) → Polarity swith goes to Positive state
POLTONEG_NOT	11	Cde In	11-12: closed (10ms pulse) → Polarity swith goes to Negative state
0V	12	GND

SKPOLCTRL 12-pin male Burndy Connector Pin assignment, located on Polarity Switch Front Panel edms

Signal	Pin	Cde/Status	Description
POLSW_FAULT1+	1	Status Out	1-2: open → Polarity Switch in fault. POLSW_FAULT1 = POLSW_FAULT Isolated Contact
POLSW_FAULT1-	2	Status Out
POLSW_INTLK1+	3	Intlk In	3-4: open → Polarity Switch will not change state, ignoring such command (POLSW_LOCKED state). Pol. Switch Grounded locally
POLSW_INTLK1-	4	Intlk In

SKPOLINTLK1 4-pins male Burndy Connector Pin assignment, located on Polarity Switch Front Panel edms

Polarity Switch Connector Interfaces Overview

Polarity Switch Signals Chronogram Polarity Switch Signals Chronogram

Power Unit

Polarity Switch is based on DC-Contactors (Bi-stable type) providing the capability of inverting the load output polarity.

Power Module is compatible with 19'' standard dimensions.

Cooling type	Fans
Power Module Weight	≈ 25kg

See below a quick overview of the schematics.

Polarity Switch Pos. Polarity Switch Pos. - Polarity Switch Neg. Polarity Switch Neg

Polarity Switch simplified Topology .vsd

Magnet Protection

Polarity Switch is part of magnet protection scheme, even if not directly fully responsible of the monitoring and diagnostic of the superconductive magnet status.

Power Switch is then expected to:

Not be activated (opening the ouput load current path) while current is not below a treshold limit (sufficiently low not to damage its contact, referring to magnet energy being stored, even at low current)

Case 1 Case 1 - Case 2 Case 2 - Case 3 Case 3 - Case 4 Case 4 Case 7

Polarity Switch simplified Architecture .vsd

Power Unit Components .vsd

Power Unit including
- 4x Control Card
- 1x PSU Card
- 1x Front Panel Card
- 16x DC bistable type Contactors

Machine Installation

Max Air losses	Control Side (incl. fans)	≈ 70 Watts
	Conduction Losses (per circuit)	≈ 40 W = 0.480V * 80 A
Building	Bat xxx

Production Contract & Contact History

http://base.web.cern.ch/

Production	2 Pc A4.4x80
	2014 - (BASE - 1 x Unit in operation + 1x unit spare)
Production	1 Pc A4.4x80
	2014 - Spare internal study

Converter Circuit Names

Type	Equipement variations
Type	Individual Circuits	I._nom. per circuit [A]	Interlock Connectors per circuit	Internal Power Latched Contactor	Free Wheel Diode	Movable Treshold Current [A]	Rear DC Connection	Rear AC Connection
A4.4x080	4	080	1	GXL14 2-p.Bistable 400A Gigavac	Optional	1	Combitac_AC+DC DC:100A_max/pin d8 [25; 35] mm²
A2.2x300 A2.1x300	2 1	300	2	GXL14 2-p.Bistable 400A Gigavac		2	Combitac_AC+DC DC:100A_max/pin d8 [25; 35] mm²
A1.1x700	1	700	2	MXL14 2-p.Bistable 400A Gigavac		5	Busbars 40x8mm-M16	Burdny 1Ph+N+PE

Overview of the different possible latched contactors studied .xls