Abstract

In modern power electronics systems, the choice of high-voltage rectifier diodes directly determines the equipment's energy efficiency boundaries and reliability limits. Through 5 real-world engineering cases, this article details how HVC (HVD series) helped customers solve excessive temperature rise, EMI interference, and supply chain bottlenecks caused by Diotec products in critical scenarios like medical CT, industrial frequency conversion, and EV fast charging — achieving dual optimization of system performance and cost.

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Case Study One: Medical Imaging

Project: 128-Slice CT Scanner High-Voltage Power Module Upgrade

1.1 Customer Challenge

A global TOP3 medical equipment manufacturer encountered bottlenecks in developing a new generation of CT scanners. Their 120kV high-voltage generator originally used Diotec brand diodes, but exposed the following issues during high-frequency continuous scanning:

• Thermal Failure Risk: Reverse recovery time (Trr) >500ns led to sharp increases in switching losses, with module temperature rising to 85°C — approaching safety limits.
• Artifact Interference: Reverse leakage current (IR) drifted at high temperatures, increasing voltage ripple and degrading imaging clarity.
• EMI Exceeding Standards: Strong reverse recovery spike noise forced engineers to add expensive filtering circuits, increasing cost and occupying valuable space.

1.2 HVC Solution

After 3 rounds of rigorous testing, the customer selected HVC HVD-SL Series (5kV High Voltage Diodes) as the replacement.

• Technical Upgrade: Optimized doping process shortened Trr to within 400ns (20% faster than the original).
• Design Margin: Single-unit withstand voltage (PIV) of 5kV provides ample safety margin for the 120kV series stack.
• Compliance Assurance: Fully compliant with IEC 60747-2; passed 2000 hours of High Temperature Reverse Bias (HTRB) testing.

1.3 Implementation Results

Diotec Model	HVC Alternative	Original Issue	Improvement
Diotec HVD	HVD-SL Series	Module Temp 85°C	65°C (-20°C)
Diotec HVD	HVD-SL Series	Efficiency 91.0%	94.0% (+3.0%)
Diotec HVD	HVD-SL Series	EMI Baseline	-18dB
Diotec HVD	HVD-SL Series	Volume Baseline	-15%

"HVC's diodes not only solved the thermal management challenge — more importantly, they maintained 100% on-time delivery during the chip shortage, ensuring our new products launched on schedule." — R&D Director Dr. Weber

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Case Study Two: Industrial Automation

Project: 500kW Steel Rolling Mill Inverter Rectifier Bridge Optimization

2.1 Customer Challenge

A large steel enterprise's rolling mill drive system faced severe energy consumption and maintenance issues with the original Diotec rectification solution:

• High Energy Consumption: High conduction losses in the rectifier bridge; a single inverter consumed over 4 million kWh annually.
• High-Temperature Derating: During summer, overheating forced the system to derate, directly impacting steel production output.
• Frequent Maintenance: 2–3 fault replacements per year, leading to high unplanned downtime costs.

2.2 HVC Solution

HVC's technical team customized the HVD-DBI Series (1600V Rectifier Module).

• Low-Loss Design: Forward voltage drop (VF) reduced by 0.15V, significantly decreasing conduction losses.
• Enhanced Heat Dissipation: DBC (Direct Bonded Copper) ceramic substrate packaging; thermal resistance as low as 2.3°C/W, improving heat dissipation by 30%.
• High Reliability: Passed 1000 hours of High Temperature and Humidity (THB) testing.

2.3 Implementation Results

• Energy Savings: System efficiency rose from 92% to 94.5%; electricity savings exceed ¥100,000/year per device.
• Production Assurance: Rectifier bridge temperature rise reduced by 12°C, eliminating summer derating issues entirely.
• Maintenance Costs: Zero faults within 18 months post-switch; ROI achieved in just 8 months.

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Case Study Three: New Energy (EV Fast Charging)

Project: 120kW DC Fast Charging Pile Rectifier Module

3.1 Customer Challenge

A charging pile manufacturer found that the original Diotec solution required a bulky air-cooling heatsink at full load. Switching noise also caused grid harmonics (THD) to exceed standards, risking failure in grid connection tests.

3.2 HVC Solution

Recommended HVD-2000 Series (2kV High Voltage Diodes).

• Soft Recovery Characteristics: Optimized S-factor significantly reduces voltage spikes and ringing during turn-off, lowering EMI at the source.
• Wide Temperature Stability: Parameter drift < 5% in extreme outdoor environments from -40°C to +85°C.

3.3 Implementation Results

• Efficiency Breakthrough: Rectification efficiency reached 97.5% (+1.5%).
• Cost Optimization: Reduced heat generation enabled a 30% smaller heatsink, directly lowering structural costs.
• Grid Compliance: THD dropped from 8% to 5%, passing national grid certification. Over 5,000 units deployed; cumulative failure rate < 0.05%.

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Case Study Four: HVAC

Project: High-End Inverter Air Conditioner Rectifier Circuit

4.1 Customer Challenge

A major home appliance manufacturer faced a CE certification crisis for its high-end air conditioners exported to Europe. The original solution failed EMI tests, and repair rates were elevated in Southeast Asia's high-humidity markets.

4.2 HVC Solution

Introduced the HVD-1500 Series.

• High-Reliability Passivation: SIPOS (Semi-Insulating Polycrystalline Silicon) passivation technology blocks moisture and ion migration — ideal for high-temperature, high-humidity environments.
• EMI Optimization: Customized reverse recovery curve smooths current transients.
• Cost Advantage: Supply chain integration delivers pricing 12% lower than Diotec.

4.3 Implementation Results

• Quality Improvement: Repair rate dropped from 1.2% to 0.5%.
• Market Access: Successfully passed CE certification EMI testing.
• Strategic Partnership: Annual sales exceeded 1 million units; HVC elevated to strategic core supplier status.

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Case Study Five: Data Center Power

Project: 3kW Server Communication Power Supply (SMPS)

5.1 Customer Challenge

Data centers are extremely sensitive to PUE (Power Usage Effectiveness). The original solution offered only 90% efficiency and low power density — insufficient for next-generation server rack space constraints.

5.2 HVC Solution

Provided HVD-DBI25 (1200V Fast Recovery Rectifier Bridge).

• Ultra-Fast Switching: Trr < 300ns — dramatically reduces high-frequency switching losses.
• Compact Package: Optimized PCB layout recommendations minimize parasitic inductance.
• Rapid Delivery: Local inventory pool supporting 2-week delivery.

5.3 Implementation Results

• Green Energy Saving: Efficiency improved to 93%, significantly reducing operating electricity costs.
• Miniaturization: Power density increased by 25%, freeing more rack space for computing hardware.

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Conclusion

From micron-level CT imaging to megawatt-scale steel rolling mills, these 5 cases demonstrate the perfect balance of extreme performance and engineering implementation in HVC high-voltage rectifier diodes.

Choosing HVC means more than a single diode — you gain a complete solution encompassing thermal management optimization, EMI suppression, and a flexible supply chain. HVC is ready to support your smooth transition from Diotec toward a higher-efficiency future.

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Diotec High Voltage Diode Cross-Reference Table

Diotec Model	HVC Alternative	Peak Reverse Voltage (kV)	Avg Forward Current (mA)	Surge Current (A)
2CL2FL	HVD-2CL2FL	15	120	10
2CL71	HVD-2CL71	8	5	0.5
2CL71A	HVD-2CL71A	8	5	0.5
2CL72A	HVD-2CL72A	10	5	0.5
2CL73A	HVD-2CL73A	12	5	0.5
2CL74A	HVD-2CL74A	14	5	0.5
2CL75	HVD-2CL75	16	5	0.5
2CL75A	HVD-2CL75A	16	5	0.5
2CL85	HVD-2CL85	16	50	3
BV6	HVD-BV6	6	100	15
BY4	HVD-BY4	4	1000	30
BY6	HVD-BY6	6	1000	30
BY8	HVD-BY8	8	500	30
BY12	HVD-BY12	12	500	30
BY16	HVD-BY16	16	300	30
DD300	HVD-DD300	3	20	3
DD600	HVD-DD600	6	20	3
DD1000	HVD-DD1000	10	20	0.5
DD1200	HVD-DD1200	12	20	3
DD1400	HVD-DD1400	14	20	3
DD1600	HVD-DD1600	14	20	3
DD1800	HVD-DD1800	18	20	3
HV4	HVD-HV4	4	200	27
HV5	HVD-HV5	5	200	27
HV6	HVD-HV6	6	200	27

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Disclaimer: Technical parameters are for reference only. Refer to the latest datasheet for actual specifications.