Power Systems Design Services

myzesaconnect.co.zw — Professional engineering services for 33kV and 132kV networks, substation primary and secondary systems, and substation civil works.

Beyond helping households and businesses get connected to ZESA, myzesaconnect.co.zw offers professional power system design services for developers, industrial customers, mining operations, and utilities requiring 33kV and 132kV infrastructure — from initial network studies through to fully detailed substation design. This work is delivered through our partner Grid Labs (see our Partners page), who carry out the engineering design under the myzesaconnect umbrella.

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33kV Power System Design

For distribution-level networks feeding industrial sites, mines, farms, and commercial developments, we provide:

• Network studies — load flow, fault level, and voltage drop studies to confirm a proposed 33kV connection or extension is technically sound before construction begins.
• Line and cable route design — overhead line design (pole/tower spotting, conductor selection, sag-tension calculations) and underground cable route design where overhead access isn’t practical.
• Protection coordination — relay setting studies and protection grading across the 33kV network to ensure faults are cleared selectively, without unnecessary wide-area outages.
• Ring main unit (RMU) and switchgear specification — sizing and specifying switchgear correctly for the network’s fault level and future load growth.
• Connection studies for embedded generation — where a 33kV connection includes solar, mini-hydro, or other generation, we assess reverse power flow, protection implications, and compliance with relevant grid code requirements.

132kV Power System Design

For larger industrial loads, mine supplies, or transmission-adjacent connections, our 132kV design services include:

• Feasibility and connection studies — assessing the most viable connection point on the existing 132kV network, including thermal and voltage constraint checks.
• Steady-state and fault level studies — using industry-standard power system modelling to confirm the network can absorb the new load or generation without breaching equipment ratings.
• Transmission line design support — tower/pole spacing, conductor and insulation coordination, and clearance compliance for 132kV overhead lines.
• Protection and control philosophy — developing the protection philosophy for new 132kV bays, including distance protection, busbar protection, and interlocking schemes.
• Grid code compliance documentation — preparing the technical submissions typically required to connect new load or generation at this voltage level.

Primary Systems Design

Primary systems are the high-voltage equipment that actually carries and switches power through a substation. Our primary systems design scope covers:

• Power transformer specification — sizing, impedance, tap-changer, and cooling requirements matched to present and forecast load.
• Switchgear design — circuit breakers, disconnectors, and busbar arrangements (single busbar, double busbar, ring, or mesh configurations) selected for the site’s reliability requirements.
• Earthing and lightning protection — substation earth grid design and lightning/surge protection coordinated with equipment insulation levels.
• Busbar and cable sizing — current-carrying capacity and fault-withstand calculations for all primary conductors.
• Single line diagram (SLD) development — the master electrical drawing that ties the entire primary system together, used as the reference for all subsequent detailed design.

Secondary Systems Design

Secondary systems are the protection, control, metering, and auxiliary systems that make a substation safe, monitored, and operable. This includes:

• Protection relay design — specification and setting calculation for overcurrent, differential, distance, and busbar protection relays appropriate to the voltage level and network configuration.
• Control and SCADA integration — control panel design, and integration with SCADA/ADMS systems for remote monitoring and operation — including protocol considerations (IEC 61850, DNP3, IEC 60870-5-104) where relevant.
• Metering design — revenue and check-metering specification, ensuring compliance with utility metering standards.
• DC auxiliary supply systems — battery bank and charger sizing for protection and control power, including autonomy calculations for loss-of-AC scenarios.
• Interlocking and synchronising schemes — ensuring safe switching sequences and, where applicable, correct synchronising for parallel operation with the grid or embedded generation.

Substation Civil Works

A substation is only as reliable as the civil infrastructure supporting it. Our substation civils scope covers:

• Site layout and general arrangement drawings — positioning of transformers, switchgear, control building, and access routes to meet safety clearance and maintenance access requirements.
• Foundations — transformer plinths, equipment support structure foundations, and steelwork foundation design suited to the site’s soil conditions.
• Cable trenches and ducting — routing and sizing of cable trenches between primary equipment, control building, and the site perimeter.
• Perimeter fencing and security — safety fencing to regulatory clearance requirements, plus site security considerations.
• Drainage — oil containment/bunding design around transformers, and general site stormwater drainage.
• Access roads and hardstanding — vehicle access suited to equipment delivery (including abnormal loads such as power transformers) and ongoing maintenance access.
• Control building design — layout for control panels, battery rooms, and site offices where required.

Why Work With Us

This power systems design work is carried out by Grid Labs, our specialist design partner, bringing real utility-side planning engineering experience to 33kV, 132kV, and substation work — whether for a single project or as an extension of our group-connection model for larger developments.

Whether you need a single deliverable (a protection study, a substation SLD, a civils layout) or full design support from feasibility through to construction-ready drawings, Grid Labs scopes work to match the project rather than offering one fixed package.

Get in touch to discuss your 33kV/132kV or substation project — myzesaconnect.co.zw